Category: CBSE Class 8

Check the below Online Education NCERT MCQ Questions for Class 8 Geography Chapter 1 Extra Questions and Answers Resources Pdf free download. https://ncertmcq.com/extra-questions-for-class-8-social-science/

Online Education for Resources Class 8 Extra Questions Geography Chapter 1

Class 8 Geography Chapter 1 Extra Questions And Answers Question 1.
What is resource?
Answer:
Anything that can be used to satisfy a need is a resource.

Ncert Solutions For Class 8 Geography Chapter 1 Resources Extra Questions Question 2.
Which two factors can change substances into resources?
Answer:

1. Time and
2. Technology.

Class 8 Geography Chapter 1 Extra Questions And Answers Pdf Question 3.
Why do people are important resource?
Answer:
People are important resources because their ideas, knowledge, inventions and discoveries lead to the creation of more resources.

Resources Class 8 Extra Questions Question 4.
How resources are classified?
Answer:

• Natural,
• human-made and
• human.

Resources Class 8 Worksheets With Answers Question 5.
How natural resources are classified?
Answer:
Natural resources are classified on the basis of their

• level of development,
• use,
• origin,
• stock,
• distribution.

Class 8 Geography Chapter 1 One Mark Questions Question 6.
In India, where is energy generated by using windmills?
Answer:

• Nagercoil in Tamil Nadu
• Gujarat coast.

Geography Class 8 Chapter 1 Extra Questions Question 7.
What is human resource development?
Answer:
Improving the quality of people’s skills so that they are able to create more resources is known as human resource development.

Ncert Class 8 Geography Chapter 1 Extra Questions Question 8.
Mention few ways of conserving resources.
Answer:

• Reducing consumption,
• Recycling,
• Reusing.

Geography Chapter 1 Class 8 Extra Questions Question 9.
Name a renewable resourced
Answer:
Solar and wind energy.

Extra Questions For Class 8 Geography Chapter 1 Question 10.
Give two examples of renewable resources.
Answer:
Solar and wind energy.

Class 8 Geography Chapter 1 Extra Questions Question 11.
What are natural resources? Give few examples.
Answer:
Resources that are drawn front nature and used without much modification are called natural resources. examples: air, water, minerals.

Extra Questions For Class 8 Social Science Geography Chapter 1 Question 12.
How BSTresources be classified on the basis of the level of their development? Write one point of difference between them;
Answer:
On the Basis of the level of development, resources can be classified into two groups – actual resources and potential resources. Actual resources are those whose quantity is known whereas the entire quantity of potential resources may not be known.

Class 8 Geo Ch 1 Extra Questions Question 13.
Distinguish between abiotic and biotic resources.
Answer:
Abiotic resources are non-living. For example, soils, rocks and minerals.
Biotic resources are living. For example, plants and animals.

Class 8 Resources Extra Questions Question 14.
What are human-made resources?
Answer:
People use natural resources to make buildings, bridges, roads, machinery and vehicles. These are known as human-made resources.

Class 8 Geography Ch 1 Extra Questions Question 15.
What is the difference between resource conservation and sustainable development?
Answer:
Using resources carefully and giving them time to get renewed is called’ resource conservation.
Balancing the need to use resources and also conserve them for the future is called sustainable development.

Class 8 Geography Chapter 1 Important Questions Question 16.
How can we contribute to maintain and preserve the life support system?
Answer:

• The diversity of life on the earth must be conserved.
• The damage to natural environment system should be minimised.

Extra Questions Of Chapter 1 Geography Class 8 Question 17.
‘Bulb should be switched off when not need’. Do you agree with this statement? If yes, give reasons.
Answer:
We should conserve energy for the future. We should using resources carefully because it is very limited.

Class 8 Geography Chapter 1 Resources Extra Questions Question 18.
What is a resource? Is human also a resource? How?
Answer:
Anything that can be used to satisfy a need is resource. YES, human is also a resource they make best use of nature to create more resource with the help of their knowledge, skill and technology.

Chapter 1 Geography Class 8 Extra Questions Question 19.
Distinguish between the renewable and non-renewable resources.
Answer:

Renewable resources	Non-renewable resources
Renewable resources get renewed or replenished quickly. Some of them are unlimited and are not affected by human activities, such as solar and wind energy.	Non-renewable resources have a limited stock. Once the stocks are exhausted, it may take thousands of years to be renewed or reply finished, For example: coal, petroleum and natural gas.

Class 8 Geography Chapter 1 Worksheet With Answers Question 20.
When was the Ministry of Human Resource Development created? What was its main aim? Which are the two important departments within this Ministry?
Answer:
The Ministry of Human Resource Development was created in 1985. Its main aim is to improve people’s skills.
Two important departments within the Ministry of Human Resource Development are :

1. The Department of School Education and Literacy
2. The Department of Higher Education.

Multiple Choice Questions (MCQs)

1. Which one of the following is a human-made resource?
(a) Minerals
(b) Rocks
(c) Means of transportation
(d) Soils.
Answer:
(c) Means of transportation.

2. Which resource among the following has no commercial value?
(a) Grandmother’s home remedies
(b) Cotton cloth
(c) Iron ore
(d) Medicinal plants.
Answer:
(a) Grandmother’s home remedies.

3. Which statement among the following is not true?
(а) Anything can be used to satisfy a need is a resource.
(b) All resources have economic or commercial value.
(c) Utility or usability is what makes an object or substance a resource.
(d) Time and technology are two important factors that can change substances into resources.
Answer:
(b) All resources have economic or commercial value.

4. Which one of the following is a Aon renewable resource?
(a) Solar energy
(b) Wind energy
(c) Water
(d) Minerals.
Answer:
(d) Minerals.

5. Non-renewable resources are……… .
(a) limited
(b) unlimited
(c) free of cost
Answer:
(a) limited.

6. Which of the following is a renewable resource?
(a) Goal
(b) Petroleum
(c) Gold
(d) Water
Answer:
(d) Water.

Glossary:

→ Resources – Anything that can be used to satisfy a need is a resource.

→ Patent – Patent means the exclusive right over any idea or invention.

→ Natural resources – Resources that sure drawn from nature and used without much modification.

→ Technology – It is the application of latest knowledge and skill in doing or making things.

→ Actual resources – Those resources whose quantity is known.

→ Potential resources – Those resources whose entire quantity may not be known and are not being used at present.

→ Abiotic resources – Resources which do not have life or non-living resources are called abiotic resources.

→ Biotic resources – Living resources or resources which have life are called biotic resources.

→ Stock of resources – It is the amount of resources available for use.

→ Renewable resources – Renewable resources are those which get renewed or replenished quickly.

→ Non-renewable resources – Those resources which are once used take thousands of years to be renewed or replenished.

→ Ubiquitous resources – Resources that are found everywhere are called ubiquitous resources.

→ Localised resources – Resources which are found only in certain places are called localised resources.

→ Human-made resources – Resources which are made by people by using natural resources are called human-made resources.

→ Resource conservation – Using resources carefully and giving them time to get renewed is called resource conservation.

→ Sustainable development – Carefully utilising the resources so that besides meeting the requirements of the present, also takes care of future generations.

Extra Questions for Class 8 Social Science

Here we are providing Class 8 History Chapter 4 Extra Questions and Answers Tribals, Dikus and the Vision of a Golden Age was designed by subject expert teachers. https://ncertmcq.com/class-8-history-chapter-4-extra-questions/

Tribals, Dikus and the Vision of a Golden Age Class 8 Extra Questions History Chapter 4

Question 1.
To which tribes did Birsa belong?
Answer:
Munda tribe.

Question 2.
Where did Munda people live?
Answer:
Munda people lived in Chhotanagpur region of the present-day state of Jharkhand.

Question 3.
Name two other tribes who were the followers of Birsa.
Answer:
Santhals and Oraons.

Question 4.
Who were called dikus?
Answer:
The outsiders were called dikus by the tribes.

Question 5.
Where were the shifting cultivators found?
Answer:
Shifting cultivators were found in the hilly and forested tracts of northeast and central India.

Question 6.
Where did the Khonds live?
Answer:
The Khond people lived in the forests of Orissa.

Question 7.
How did Khond people obtain their livelihood?
Answer:
The Khond people obtain their livelihood by hunting and food-gathering.

Question 8.
How did the forest people obtain things that they did not produce in the forests?
Answer:
They mostly exchanged goods to fulfil their need of things they did not produce.

Question 9.
What did the forest people do when supplies of forest produce shrank?
Answer:
They wandered around in search of work as labourers.

Question 10.
Name any two tribes who lived by herding and rearing animals.
Answer:
Van Gujjars and Gaddis.

Question 11.
Where did the Baiga people live?
Answer:
The Baiga people lived in the forests in Central India.

Question 12.
Name any two settled tribal groups.
Answer:
Gonds and Santhals.

Question 13.
What did the British officials think about settled tribal groups?
Answer:
The British officials thought them to be more civilised than hunter-gatherers.

Question 14.
With which tribal groups the British were uncomfortable?
Answer:
The British were uncomfortable with those tribal groups who moved about and did not have a fixed home.

Question 15.
Why did the British want tribes to become peasant cultivators?
Answer:
This was because peasants were easier to control and administer than people who were always on move.

Question 16.
What were the Reserve Forests?
Answer:
They were the forests which produced timbers. The tribal people were not allowed to enter these forests.

Question 17.
Why were the forest villages established?
Answer:
The forest villages were established to ensure a regular supply of cheap labour for cutting trees for railway sleepers.

Question 18.
When and where did the revolt of Sonogram Sangma take place?
Answer:
The Sonogram Sangma revolt took place in 1906 in Assam.

Question 19.
When and where did the Forest Satyagraha take place?
Answer:
The Forest Satyagraha took place in the 1930s in the Central Provinces.

Question 20.
Name the tribe which reared cocoons.
Answer:
Santhals of Hazaribagh.

Question 21.
Where did tribes work as labourers in the late nineteenth century?
Answer:
They worked in tea plantations of Assam and coal mines of Jharkhand.

Question 22.
What was the aim of Birsa’s movement?
Answer:
His movement aimed at reforming tribal society and take it out of the hands of dikus.

Question 23.
What did people think about Birsa? What did Birsa proclaim about himself?
Answer:

• People believed that Birsa could cure all diseases and multiply grains.
• Birsa proclaimed about himself that God has appointed him to save his people from trouble and free them from the slavery of dikus.

Question 24.
Why were the Munda and other tribal people of the region unhappy with the British rule?
Answer:

• They were unhappy with the changes they were experiencing and the problems they were facing under the British rule.
• Their ways of life seemed to be disappearing, their livelihoods were under threat, and their religion appeared to be in danger.

Question 25.
Comment on tribal societies.
Answer:

• Most tribes had customs and rituals different from those laid down by Brahmins.
• The tribal societies did not have the same social divisions that were characteristics of caste societies.
• People who belonged to the same tribe thought of themselves as sharing common ties of kinship.

Question 26.
How did the shifting cultivators live their lives?
Answer:

• The lives of the shifting cultivators depended on free movement within the forest.
• Their lives depended on being able to use the land and forests for growing their crops.

Question 27.
What did the tribal people do when supplies of forest produce shrank?
Answer:

• Some of the tribal people did odd jobs in the villages.
• They carried load or got jobs in building roads.
• Some people laboured in the fields of peasants and farmers.

Question 28.
Why were Baiga people reluctant to do works for others?
Answer:

• The Baigas saw themselves as people of the forest, who could only live on the produce of the forest.
• The Baiga people considered it to be below the dignity of a Baiga to become a labourer.

Question 29.
Why did tribal people become dependent on traders and moneylenders?
Answer:
Following were the reasons of their dependence :

• The tribal people often needed to sell and buy goods in order to be able to get those goods which were not produced in their locality.
• Traders came around with things for sale. Money-lenders gave loans with which the tribals could meet their cash needs.

Question 30.
Why did the tribal people see moneylenders and traders as evil outsiders?
Answer:

• The traders sold them things at high prices and purchased goods from them at low prices.
• The moneylenders charged high-interest rates on the loans which they provided to the tribal people.
  This led to indebtedness and poverty among the tribal people. This was because they saw them as evil outsiders.

Question 31.
Discuss some herders and animal rearing tribal people.
Answer:

• The Van Gujjars of the Punjab hills and the Labadie of Andhra Pradesh were cattle herders.
• The Gaddis of Kulu were shepherds.
• The Bakarwals of Kashmir reared goats.

Question 32.
Discuss the state of rights of the land among Mundas.
Answer:

• Among Mundas, the land belonged to the Clan as a whole.
• All members of the Clan were regarded as descendants of the original settlers, who has first cleared the land. Therefore, all of them had the rights on land.

Question 33.
What happened to the British effort to settle jhum cultivators?
Answer:

• This effort was not very successful.
• Settled plough cultivation was not easy in the areas where water was scarce and the soil was dry.
• Jhum cultivators who undertook the plough cultivation often suffered, since their fields did not produce good yields. People started protesting settled ploughing.

Question 34.
Explain the reformist ideas of Birsa.
Answer:

• Birsa asked people to give up drinking liquor which was devastating people’s personal, family and social life.
• He urged people to clean their village and stop believing in witchcraft and sorcery.

Question 35.
What were the political aims of Birsa movement?
Answer:

• Birsa wanted to drive out missionaries, money-lenders, Hindu landlords and the government.
• This movement wanted to set up a Munda Raj with Birsa as its head.

Question 36.
Why did Munda people consider dikes as the cause of their misery and sufferings?
Answer:

• They felt that the land policies of the British were destroying their traditional land system.
• They saw that Hindu landlords and moneylenders were taking over their land.
• They saw that the missionaries were criticising their traditional culture.

Question 37.
What is colonial rules?
Answer:
When the powerful country has been administration the land and resource of a country it is called colonial rules.

Question 38.
What were the two main systems of indigo cultivation?
Answer:

1. NIJ-cultivation on planter’s own land.
2. ryoti-cultivation on ryot’s land.

Question 39.
Explain jhum cultivation.
Answer:

• This was done on small patches of land, mostly in the forest.
• The cultivators cut the trees and burnt the vegetation to clear the land for cultivation.
• They spread ash throughout the land. They did not plough the land.
• They broadcasted the seeds.
• Once the crop was ready and harvested, they moved to another field to follow the same process.
  This is because this is also known as shifting cultivation.

Question. 40.
Discuss the hunting and gathering amongst the Khonds.
Answer:

• The Khonds lived in the forests of Orissa. They were hunters and gatherers.
• They regularly went out on collective hunts and then divided the meat amongst themselves.
• They ate fruits and roots they collected from forests. They also cooked foods using oil extracted from the seeds of sal and mahua.
• They collected medicinal herbs and shrubs from the forest and sold them in the local market.
• They collected Kusum and Palash flowers from the forests and supplied them to the local weavers and leather workers.

Question 41.
What was the status of tribal chiefs before the arrival of the British?
Answer:

• In many areas, tribal chiefs were important people.
• They enjoyed a certain amount of economic power and had the right to administer and control their territories.
• In some places, they had their own police and decided on the local rules of land and forest management.

Question 42.
How was the tribal life affected by the forest laws?
Answer:

• The British extended their control over all forests and declared that forests were state property.
• Some forests were classified as Reserved Forests.
• In these forests, people were not allowed to move freely.
• They were prevented from practising jhum cultivation, collecting fruits or hunting animals in these forests.

Question 43.
In what ways was the Birsa movement important?
Answer:
This movement was important in the following two ways :

1. It forced the colonial government to introduce land laws in favour of the tribal people so that the dikus could not easily take over tribal lands.
2. It showed once again that the tribal people had the capacity to protest against injustice. They were able to express their anger against the exploitative and oppressive colonial rule.

Question 44.
What problems did shifting cultivators face under the British rule.
Answer:

• The Jhum cultivators who took to plough cultivation as per the British model often suffered.
• The fields did not produce good yields.
• Cultivators had to pay revenue fixed by the British.
• They wanted to shift back to the Jhum cultivation.
• Finally, they had to protest this new method.

Multiple Choice Questions (MCQs)

1. Birsa was born in a family of a tribal group that lived in Chhotanagpur in Bihar.
(a) Mundas
(b) Santhal
(c) Orion
(d) Gonds.
Answer:
(a) Mundas.

2. Tick the correct pair in the following.
(а) Fallow-field is cultivated every year.
(b) Khonds – Gujarat.
(c) Baigas – Rajasthan.
(d) Jhum cultivation – shifting cultivation.
Answer:
(d) Jhum cultivation – shifting cultivation.

3. Which statement is not correct in the following?
(a) The Bakarwals of Kulu were shepherds.
(b) Shifting cultivators were found in the hilly and forested tracts of northeast and central India.
(c) The Van Gujjars of the Punjab hills were cattle herders.
(d) It was below the dignity of a Baiga to become a labourer.
Answer:
(c) The Van Gujjars of the Punjab hills were cattle herders.

4. Which is not a correct statement in the following?
(а) Verrier Elwin was a British anthropologist who lived among the Baigas and Khonds of Central India for many years.
(b) Among the Mundas of Chhota- Nagpur, the land belonged to the clan as a whole.
(c) Under the British rule, the functions and powers of the tribal chiefs changed considerably.
(d) The British officials saw shifting cultivators as more civilised than the Gonds and the Santhals.
Answer:
(d) The British officials saw shifting cultivators as more civilised than the Gonds and the Santhals.

5. How did Birsa Munda die in 1900?
(a) Died of plague
(b) Died of cholera
(c) He was hanged
(d) He was shot dead.
Answer:
(b) Died of cholera.

Glossary:

→ Fallow -A field left uncultivated for a while so that the soil recovers fertility.

→ Sal – A tree.

→ Mahua -A flower that is eaten or used to make alcohol.

→ Beware – A term used in Madhya Pradesh for shifting cultivation.

→ Sleeper – The horizontal planks of wood on which railway lines are laid.

→ ‘ Vaishnav-Worshippers of Lord Vishnu.

Extra Questions for Class 8 Social Science

Here we are providing Online Education Materials: Metals and Non-Metals Extra Questions for Class 8 Science Chapter 4 was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-8-science/

Online Education for Class 8 Science Chapter 4 Extra Questions and Answers Materials: Metals and Non-Metals

Materials Metals And Non Metals Class 8 Questions And Answers Question 1.
Do non-metals produce ringing sound?
Answer:
No, non-metals do not produce the ringing sound. It is a property of metals only.

Materials: Metals And Non Metals Class 8 Questions And Answers Question 2.
List the characteristic properties of metals.
Answer:
The metals have the following properties :

• Hardness,
• lustre,
• malleability
• ductility,
• sonority, and
• good conductivity of heat and electricity.

Metals And Non Metals Class 8 Question 3.
Name some metals.
Answer:
Iron, copper, gold, aluminium, magnesium, etc.

Cbse Class 8 Science Metals And Nonmetals Question 4.
Give some examples of non-metals.
Answer:
Sulphur, carbon, oxygen, phosphorus, calcium, etc.

Metals And Non Metals Class 8 Extra Questions Question 5.
Name two metals which can be cut with knife.
Answer:
Sodium and potassium are two metals which are soft and can be cut with a knife.

Metal And Non Metals Class 8 Question 6.
Name a metal which is found in liquid state at room temperature.
Answer:
Mercury.

Materials Metals And Non Metals Questions And Answers Question 7.
Write the equation of rusting of iron.
Answer:
3Fe + 2H₂O + O₂ → Fe₃O₄ + 2H₂.

Extra Questions On Metals And Non-Metals Class 8 Question 8.
If the red litmus placed in a solution turns blue, the solution is called hydroxides.
Answer:
Basic.

Class 8th Science Chapter 4 Extra Questions Question 9.
If the blue litmus paper turns red, the solution is called hydroxides.
Answer:
Acidic.

Class 8 Science Ch 4 Extra Questions Question 10.
When sulphur reacts in air (O₂), what is the product formed.
Answer:
It is sulphur dioxide (SO₂).

Class 8 Metals And Nonmetals Extra Questions Question 11.
What is formed when sulphur dioxide is dissolved in water? Also, write the equation.
Answer:
Sulphurous acid is formed.
SO₂ + H₂O →H₂SO₃ (Sulphurous acid).

Metal And Non Metal Class 8 Question 12.
What happens when a blue litmus paper is treated with an acid?
Answer:
The blue litmus paper turns red.

Science Class 8 Metals And Non Metals Question 13.
Name the non-metals in the following acids :
Sulphuric acid (H₂SO₄), Hydrochloric acid (HCl) and Nitric acid (HNO₃).
Answer:
Sulphur, chlorine and nitrogen respectively.

Materials Metals And Nonmetals Class 8 Questions And Answers Question 14.
What happens when a small piece of sodium metal is placed in water?
Answer:
The metal piece starts moving in water with a hissing sound and then it catches fire.

Metals And Nonmetals Class 8 Questions Answers Question 15.
Why are metals used in making machinery?
Answer:
Metals are very hard, can withstand very high temperatures and are strong as well as lustrous. That is why they are used “in making various machinery.

Question 16.
Define element.
Answer:
The substances made up of only one type of atoms are called elements. Sulphur, iron, gold, calcium, hydrogen, etc. are elements. There are about 92 elements. Most of the elements are metals.

Question 17.
What is an atom?
Answer:
An atom is the smallest unit of an element. The atom of an element remains unaffected by any physical change in the element.

Question 18.
Describe how metallic and non-metallic oxides are formed.
Answer:
On burning, metals react with oxygen to produce metal oxides which are basic in nature. Non-metals react with oxygen to produce non-metallic oxides which are acidic in nature.

Question 19.
How can metals be distinguished from non-metals?
Answer:
Metals can be distinguished from non-metals on the basis of their physical and chemical properties.

Question 20.
Define malleability of a metallic substance. ‘
Answer:
The property of metals by which they can be beaten into thin sheets is called malleability. This is the characteristic property of metals.

Question 21.
Why is sodium stored in kerosene?
Answer:
Sodium metal is very reactive. It reacts vigorously with oxygen and water. A lot of heat is generated in the reaction. Therefore it is stored in kerosene to avoid its contact with air and water.

Question 22.
Explain the construction of a water filter with materials available at home.
Answer:
(a) Cut off the bottom of a plastic bottle and place the bottle upside down into the vase or tall drinking glass.

(b) Place cotton balls, cloth, or a coffee filter inside the bottle as the first layer. Add an inch of activated charcoal as the second layer. Over the charcoal, add about two inches of small stones as the third layer and add about three to four inches of clean sand on top of the gravel.

(c) Add gravel to the bottle as the final layer. Leave about a half-inch of space from the top of the upside-down bottle.

(d) Pour the glass of muddy water on top of the homemade water filter and watch the water drip clean into the glass below.

Question 23.
How metal reacts with
(a) Oxygen,
(b) Water and
(c) Acids
Answer:
(a) Metals react with oxygen and form their oxides.
Magnesium (Mg) + Oxygen (O₂) → Magnesium Oxide (MgO)
Sodium (Na) + Oxygen (O₂) → Sodium oxide (Na₂O)

(b) Metals react with water differently. Metals like sodium reacts with water vigorously and a lot of heat is produced. Whereas iron reacts with water slowly.
Sodium (Na) + Water (H₂O) → Sodium hydroxide (NaOH) + Hydrogen gas (H₂)

(c) Metals react with dilute acids and produce hydrogen gas that burns with a ‘pop’ sound.
Zinc (Zn) + Hydrochloric acid (HCl) → Sodium chloride (NaCl) + Hydrogen gas (H₂).

Question 24.
(a) What is a displacement reaction? Give an example for it.
(b) Which gas is released when acid reacts with a metal?
Answer:
(a) The chemical reaction in which a more reactive metal displaces/replaces a less reactive metal from its salt solution is called a displacement reaction. But a less reactive metal cannot replace a more reactive metal.
Copper sulphate (CuSO₄) + Zinc (Zn) (Blue) → Zinc sulphate (ZnSO₄) + Copper (Cu) (Colourless) (Reddish brown)

(b) Hydrogen gas is released when acid reacts with a metal.
Sodium (Na) + Water (H₂O) → Sodium Hydroxide (NaOH) + Hydrogen gas (H₂).

Question 25.
Write down three uses of metals and two uses of non-metals.
Answer:
Uses of metals :

• Metals are used in making machinery, automobiles, aeroplanes, trains, satellites and industrial gadgets, etc.
• Metals are used in making cooking utensils, water boilers, etc.
• Metals are used in making decorative arts, jewellery and coins.
• Aluminium foils are used for packaging medicines, chocolates, decorating sweets, wrapping food, etc.

Uses of non-metals :

• Non-metal essential for our life which all living beings inhale during breathing.
• Non-metals used in fertilisers to enhance the growth of plants.
• Non-metal used in water purification process.
• Non-metals used in crackers.

Multiple Choice Questions (MCQs)

1. Which is the industry responsible for corrosion of marble of the Taj Mahal?
(a) Textile industry
(b) Paper industry
(c) Steel industry
(d) Oil refinery.
Answer:
(d) Oil refinery.

2. Name the suffocating and corrosive gas.
(a) Carbon dioxide
(b) Sulphur dioxide
(c) Oxygen
Answer:
(b) Sulphur dioxide.

Extra Questions for Class 8 Science

Here we are providing Online Education Coal and Petroleum Class 8 Extra Questions and Answers Science Chapter 5 was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-8-science/

Online Education for Class 8 Science Chapter 5 Extra Questions and Answers Coal and Petroleum

Extra Questions For Class 8 Science With Answers Question 1.
Name three natural resources.
Answer:
Air, water and soil.

Coal And Petroleum Class 8 Questions And Answers Question 2.
Why air, water, minerals and soil are called natural resources?
Answer:
Because they are provided by nature. Human beings cannot make them.

Coal And Petroleum Class 8 Notes Questions And Answers Question 3.
Name two inexhaustible natural resources.
Answer:
Sunlight and air.

Coal And Petroleum Class 8 Question 4.
Name two exhaustible resources.
Answer:
Wildlife and minerals.

Class 8 Science Extra Questions Question 5.
Name the gas produced during destructive distillation of coal.
Answer:
Coal gas.

Coal Is An Example Of Class 8 Question 6.
What happens when a burning matchstick is taken near the mouth of the outlet tube during destructive distillation of coal?
Answer:
Coal gas catches fire.

Learn Insta Class 8 Extra Questions Question 7.
Name the black residue left behind in the glass tube during destructive distillation of coal.
Answer:
It is coke.

Coal And Petroleum Class 8 Question Answer Question 8.
What is the name of the process in which coal is heated in absence of air.
Answer:
The process is called destructive distillation of coal.

Coal And Petroleum Class 8 Pdf Question 9.
Name the pure form of carbon.
Answer:
The pure form of carbon is coke.

Extra Questions Class 8 Science Question 10.
How is coal gas used nowadays?
Answer:
Nowadays the coal gas is used as a source of heat rather than light.

Ncert Science Book Class 8 Extra Questions With Answers Question 11.
Where was the first oil well drilled?
Answer:
The world’s first oil well was drilled at Pennsylvania, USA in 1859.

Extra Questions Of Science Class 8 Question 12.
When and where was the first oil well drilled in India?
Answer:
In 1867 at Makum in Assam.

Extra Questions For Class 8 Science Question 13.
What is the name of the process of separating the different constituents fractions of petroleum?
Answer:
It is called refining.

Extra Question Of Class 8 Science Question 14.
What is the full form of PCRA?
Answer:
Full form of PCRA is Petroleum Conservation Research Association.

Extra Questions Of Class 8 Science Question 15.
What is termed as black gold?
Answer:
Coal is termed as black gold.

Question 16.
Define fossil fuel.
Answer:
Fossil fuel: The exhaustible natural resources like coal, petroleum and natural gas which were formed from the dead remains of living organisms (fossils) are called fossil fuels. They are found in the earth’s crust.

Question 17.
Define LPG.
Answer:
LPG is Liquefied Petroleum Gas. It is obtained during fractional distillation of petroleum. Its main components are: butane and propane. It is used in filling cylinders and for cooking purposes. It is also used as an industrial fuel.

Question 18.
Define inexhaustible natural resources.
Answer:
Those resources, which are present in unlimited quantity in nature and are not likely to be exhausted by human activities are called inexhaustible natural resources e.g., sunlight, air, etc.

Question 19.
Define exhaustible natural resources.
Answer:
The resources, which are present in limited quantity in nature and can be exhausted by human activities are called exhaustible natural resources e.g., forests, wildlife, minerals, coal, petroleum, natural as, etc.

Question 20.
How were exhaustible natural resources formed?
Answer:
These were formed from the dead remains of living organisms (fossils). So, these are also known as fossil fuels.

Question 21.
What gas is produced when coal is heated in air?
Answer:
When coal is heated in air, a gas called carbon dioxide (CO₂) is formed, which is a harmful gas and its presence in excess causes greenhouse effect and global warming.

Question 22.
Why is coal called fossil fuel?
Answer:
Since coal was formed from the remains of the vegetations (plants), it is called a fossil fuel.

Question 23.
Define carbonisation.
Answer:
The slow process of conversion of dead vegetation into coal is called carbonisation.

Question 24.
What do you mean by destructive distillation?
Answer:
The process of heating coal in the absence of air (oxygen) is called destructive distillation.

Question 25.
From where naphthalene balls are obtained? What is its use?
Answer:
Naphthalene balls are obtained from the coal tar. These balls are used to repel” insects and moths.

Question 26.
What fuel is used in heavy motor vehicles?
Answer:
Diesel is used as fuel in heavy motor vehicles.

Question 27.
Write any two uses of coke.
Answer:
Two uses of coke are :

1. Coke is used in the manufacture of steel.
2. Coke is used in the extraction of many metals.

Question 28.
Name the organisation in India which advises people ‘how to save petrol/ diesel’. Write its full form.
Answer:
In India, PCRA advises people ‘how to save petrol/diesel’ while driving. PCRA give important and valuable tips necessary to follow while driving. The full form of PCRA is Petroleum Conservation Research Association.

Question 29.
What are the uses of coal gas?
Answer:

• The coal gas is used as a fuel in the coal processing plant and in many industries situated near the coal processing plants.
• Earlier it was used for lighting but nowadays it is used as a source of heat.

Question 30.
What is petroleum? What is meant by refining?
Answer:
Petroleum is a dark oily liquid. It has an unpleasant smell. It is a mixture of various constituents such as petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc. The process of separating the different constituents/fractions is known as refining.

Question 31.
Write down five constituent of petroleum refining with their one use.
Answer:
Constituents of petroleum and their uses :

1. LPG: It is used as a fuel for home and industry.
2. Petrol: It is used as a motor fuel, aviation fuel, and solvent for dry cleaning.
3. Kerosene: It is used as a fuel for stoves, lamps and for jet aircrafts.
4. Diesel: It is used as a fuel for heavy motor vehicles, electric generators.
5. Lubricating oil: It is used for lubrication of moving machinery parts like fans, motors, etc.
6. Paraffin wax: Paraffin wax is used for making ointments, candles, vaseline, etc.

Question 32.
Define the following :
(a) Crude oil
(b) Coke
(c) CNG
(d) PCRA
(e) Natural gas
Answer:
(a) Crude oil: Crude oil is a dark, oily liquid with an unpleasant smell obtained from the layers of the earth crust. It is popularly termed as Petroleum. The term ‘petroleum’ has been derived from the Latin words: ‘petra’ – which means rock and ‘oleum’ – which means oil.

(b) Coke: It is a tough, porous and black substance. It is almost pure form of carbon and contains about 98% carbon. It is a good fuel and bums without smoke.

(c) CNG: Natural gas stored under high pressure in compressed form is called compressed natural gas (CNG). CNG is used for power generation. It is now being used as a fuel for transport vehicles because it is less polluting. It is a cleaner fuel.

(d) PCRA: PCRA advises people ‘how to save petrol/diesel’ while driving. PCRA give important and valuable tips necessary to follow while driving. The full form of PCRA is Petroleum Conservation Research Association.

(e) Natural gas: Natural gas is a fossil fuel found naturally as a gas mixture in the oil wells. Its main component is methane. Natural gas is a very important fossil fuel because it is easy to transport through pipes.

Question 33.
What is fuel? Write down four characteristics of an ideal fuel?
Answer:
A fuel is a substance that is burned to provide heat energy. Materials like coal, wood, diesel, natural gas etc. provide heat so used as fuels.
The characteristics of good fuel are :

1. It should be economical.
2. It should be available easily.
3. It should not emit poisonous gases on burning.
4. It should have a high calorific value.
5. It should be easy to transport and handles.
6. It should leave very little or no ash after burning.

Question 34.
Today large demand of petroleum has increased its drilling from various resources. What will happen if it continues? What steps should be taken in order to mitigate such conditions?
Answer:
The alarming increase in the demand and its drilling can lead to the following consequence :

• The reserve Or stock is limited, it will soon run away.
• Burning these fuels also cause air pollution as well as global warming.

In order to mitigate such situations, the following steps should be taken :

• We should use the fossil fuels judiciously so that they are available for a longer period.
• We must look for alternative sources, such as solar energy, tidal energy, wind energy, etc.

Multiple Choice Questions (MCQs)

1. Choose the correct statement from the following :
(a) It is difficult to transport natural gas through pipes.
(b) The disadvantage of natural gas is that it cannot be used directly for burning in homes.
(c) Natural gas is stored under high pressure as compressed natural gas.
(d) Natural gas cannot be used for power generation.
Answer:
(c) Natural gas is stored under high pressure as compressed natural gas.

2. Which gas is produced when coal is burnt :
(a) Oxygen
(b) Carbon dioxide
(c) Nitrogen
(d) Hydrogen
Answer:
(b) Carbon dioxide.

Extra Questions for Class 8 Science

Here we are providing Crop Production and Management Class 8 Extra Questions and Answers Science Chapter 1 was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-8-science/

Class 8 Science Chapter 1 Extra Questions and Answers Crop Production and Management

Crop Production And Management Class 8 Extra Questions Question 1.
Name two methods for control weed.
Answer:

1. Weeds are removed by hand uprooting.
2. Weeds are removed by using weedicides.

Crop Production And Management Class 8 Extra Questions And Answers Question 2.
Choose the correct option and rewrite the sentence again. Weeding/Feeding is the process of removal of weeds.
Answer:
Weeding is the process of removal of weeds.

Class 8 Science Chapter 1 Extra Questions And Answers Question 3.
What is the process of loosening and turning of the soil called?
Answer:
Tilling or ploughing.

Class 8 Science Ch 1 Extra Questions Question 4.
What are the big pieces of soil in the ploughed field called?
Answer:
Crumbs.

Crop Production And Management Extra Questions Question 5.
Name the main tools used for ploughing?
Answer:
Plough, hoe, and cultivator.

Class 8 Science Chapter 1 Extra Questions Question 6.
What is meant by good quality seeds?
Answer:
It means clean and healthy seeds that yield good crops both in quality and quantity.

Extra Questions For Class 8 Science Chapter 1 Question 7.
What name is given to the manure obtained from plant and animal waste?
Answer:
Organic manure.

Crop Production And Management Extra Questions And Answers Question 8.
Name the chemical substances which are rich in a particular nutrient?
Answer:
Fertilizers.

Crop Production And Management Class 8 Important Questions Question 9.
Name the bacterium present in the nodules of the roots of leguminous plants which fixes atmospheric nitrogen.
Answer:
Rhizobium.

Class 8 Crop Production And Management Extra Questions Question 10.
Name the process of supply of water to crops at different intervals?
Answer:
Irrigation.

Crop Production And Management Questions And Answers Pdf Question 11.
What are two latest irrigation methods that help us to use water economically?
Answer:
Sprinkler system and Drip system.

Crop Production And Management Class 8 Questions And Answers Question 12.
What do we call the undesirable plants which grow along with the main crop unpurposely?
Answer:
Weeds.

Extra Questions Of Chapter 1 Science Class 8 Question 13.
What is the best time for the removal of weeds?
Answer:
Before they produce flowers and seeds.

Crop Production And Management Class 8 Extra Question And Answers Question 14.
What are the chemicals used to control weeds Called? Give one example.
Answer:
Weedicides e.g., 2 and 4-D.

Crop Production And Management Class 8 Questions Question 15.
Name some traditional methods to irrigate the field.
Answer:
The various traditional ways to irrigate the fields are :

• Moat (pulley system),
• Chain pump,
• Dhekli (lever system),
• Rahat.

Question 16.
Why is weeding necessary?
Answer:
Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light.

Question 17.
What is combine and what is its use?
Answer:
Combine is a combined harvester and thresher used for harvesting and threshing.

Question 18.
Explain the term harvesting. How is it done?
Answer:
Harvesting is cutting the crop after they are matured. It is done either by manually or by machine called harvester.

Question 19.
How do we store foodgrains?
Answer:

• Dried neem leaves are used for storing food grains at home.
• For storing large quantities of grains in big godowns, specific chemical treatments are done to protect foodgrains from pest and microorganisms.

Question 20.
What precautions are undertaken before storing the foodgrains?
Answer:
Precautions undertaken before storing foodgrains are :

• Grains should be dried properly.
• Proper chemical treatment should be done to protect grains from insects, pests and microorganisms.

Question 21.
Mention any six agricultural practices.
Answer:
The activities or tasks are used as agricultural practices are listed below :

• Preparation of soil
• Sowing
• Adding manure and fertilisers
• Irrigation
• Protecting from weeds
• Harvesting
• Storage.

Question 22.
Why storage of food grains are essential? Name two structures for storage of grain.
Answer:
Storage of produce is an essential task. The harvested grains are to be kept safe from moisture insects, rats and microorganisms. Harvested grains have more moisture. So the grains are properly dried in the sun to reduce the moisture in them. This prevents the attack by insect pests, bacteria and fungi.

Methods of storing grains :

• Farmers store grains in jute bags or metallic bins.
• Large scale storage of grains is done in silos and granaries.

Question 23.
Describe the use of seed drill.
Answer:
The seed drill is used for sowing seeds with the help of tractors. This tool sows the seeds uniformly at a proper distance and depth and cover seeds by soil. This prevents damage caused by birds and also saves time and labour.

Question 24.
How is organic manure prepared?
Answer:
For preparing manure, plant and animal waste is dumped in pits at open places and allowed to decompose. The decomposition is facilitated by some microorganisms. The decomposed matter is called organic manure.

Question 25.
Why is the organic manure considered better than fertilizers?
Answer:
The organic manure is considered better than fertilizers because :

• it enhances the water holding capacity of soil.
• it makes the soil porous due to which exchange of gases becomes easy.
• it increases the number of friendly microbes.
• it improves the texture of the soil.

Question 26.
What is crop rotation? What is its advantage?
Answer:
The crop rotation is replenishment of soil with nutrients by avoiding the cultivation of the same crop year after year. It can be done by growing another crop alternately.

Question 27.
What is the benefit of irrigation?
Answer:
When crops are irrigated, nutrients get dissolved in water and get transported to each part of the plants along with water.

Question 28.
What are fertilizers and manure? How are they produced? How are they different from one another?
Answer:
The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilizers. Fertilizers are chemical substances which are rich in a particular nutrient. These are produced in factories. Manure is an organic substance which is obtained from the decomposition of plant and animal wastes.
A fertilizer is different from manure in the following ways :

Fertilizer	Manure
(i) Fertilizers are prepared in the factories.	Manure is prepared in the fields.
(ii) Fertilizers do not provide any humus to the soil.	Manure provides a lot of humus to the soil.
(iii) Fertilizers are very rich in plant nutrients like nitrogen, phosphorus and potassium.	Manure is not very rich in plant nutrients.
(iv) Fertilizer is an inorganic substance.	Manure is a natural substance obtained by the decomposition of cattle dung, human waste and plant residues.

Question 29.
(a) Why does farmer follow crop rotation practice in his field?
(b) What will happen if a farmer does not plough his. field before sowing the seeds? Write any two effects.
Answer:
(a) Crop rotation is done by growing legume crops and cereal crops like wheat alternately on the same piece of land. Rhizobium bacteria present in the nodules of the roots of leguminous plants helps in the replenishment of the soil with nitrogen. They fix atmospheric nitrogen.

(b) When a farmer doesn’t plough his field before sowing, this may have the following effects :

• Ploughing helps in proper mixing of manure in the soil and turning the soil over.
• Ploughing helps the water to go penetrate through the soil and reach the roots.
• Ploughing improves air circulation so that roots can respire easily.
• Ploughing improves the water-retaining capacity of the soil.

Question 30.
(a) What are fertilizers?
(b) Write any two disadvantages of using fertilizers excessively.
Answer:
(a) A fertilizer is an inorganic salt prepared in factories. Fertilisers are very rich in plant nutrients like nitrogen, phosphorus and potassium (NPK), urea etc.
(b)

• Fertilisers are becoming a source of water pollution.
• Excessive use of fertilisers makes the soil less fertile.
• Long-term use of chemical fertilizer changes the nature (pH) of the soil.
• Excessive application of fertilizers affects the environment negatively.

Multiple Choice Questions (MCQs)

1. Hoe is an agriculture tool for
(а) Removing weeds
(b) Loosening of soil
(c) Both (a) and (b).
Answer:
(b) Loosening of soil.

2. The process of loosening and turning of soil is called
(a) irrigation and manuring
(b) digging and winnowing
(c) tilling and ploughing
(d) harvesting and storage.
Answer:
(a) irrigation and manuring.

3. Whifeh irrigation system is best suited to avoid wastage of water?
(a) Drip system
(b) Chain pump
(c) Sprinkler
(d) Pulley system.
Answer:
(b) Chain pump.

4. Combine in an agriculture tool for
(a) harvesting
(b) threshing
(c) both
Answer:
(c) both.

Extra Questions for Class 8 Science

Check the below Online Education NCERT MCQ Questions for Combustion and Flame Class 8 Extra Questions and Answers Science Chapter 6 Pdf free download. https://ncertmcq.com/extra-questions-for-class-8-science/

Online Education for Class 8 Science Chapter 6 Extra Questions and Answers Combustion and Flame

Combustion And Flame Class 8 Questions And Answers Question 1.
Why is food called fuel for our body?
Answer:
In our body, food is broken down by reaction with oxygen and heat is produced. That is why food is called fuel for our body.

Class 8 Combustion And Flame Question Answer Question 2.
Why does a piece of wood not burn by bringing a burning matchstick near it?
Answer:
Wood has high ignition temperature. A burning matchstick cannot produce so much heat to reach the ignition temperature of wood. Therefore, wood does not burn.

Combustion And Flame Question Answer Question 3.
Why is it important for all of us to know the telephone numbers of the fire service station?
Answer:
Who knows when and where suddenly fire breaks out. The fire brigade from the fire service station could be called when fire occurs anywhere. This can be -done only when we know the telephone numbers of fire- services.

Combustion And Flame Class 8 Question Answer Question 4.
How can the fire caused by burning liquid fuels be extinguished?
Answer:
It can be extinguished by throwing sand or soil over it.

Class 8 Science Chapter 6 Short Question Answer Question 5.
Name two types of fire extinguishers.
Answer:
Soda acid fire extinguishers and hydrocarbon fire extinguishers are two types of fire extinguishers.

Combustion And Flame Class 8 Questions Answers Question 6.
Name a substance which burns itself in air.
Answer:
Phosphorus.

Combustion And Flame Class 8 Learn Insta Question 7.
Does charcoal produce a flame on burning?
Answer:
No, charcoal does not vaporise and so does not produce a flame.

Combustion And Flame Class 8 Question 8.
Which gas is formed during the incomplete combustion of any fuel?
Answer:
Carbon monoxide gas.

Combustion And Flame Class 8 Solutions Question 9.
Define calorific value of fuel.
Answer:
Calorific value: The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value. The calorific value of. a fuel is expressed in a unit called kilojoule per kg (kJ/kg). An ideal fuel has high calorific value.

Class 8 Science Chapter 6 Combustion And Flame Question Answer Question 10.
Define ignition temperature.
Answer:
Ignition temperature is the lowest temperature at which a combustible substance catches fire. An ideal fuel should have a proper ignition temperature.

Class 8 Science Chapter Combustion And Flame Question 11.
Define combustible and non-combustible substances.
Answer:
The substance that undergoes combustion is said to be combustible.
The substance that does not undergo combustion is called non-combustible.

Extra Questions For Class 8 Science With Answers Question 12.
Define ignition temperature. Do all combustible substances have same ignition temperature?
Answer:
The lowest temperature at which a substance catches fire is called its ignition temperature.
All combustible substances do not have same ignition temperature. In fact, each combustible substance has i different ignition temperature.

Ncert Science Book Class 8 Extra Questions With Answers Question 13.
Does combustible substance catch fire on its own? Why?
Answer:
A combustible substance does not catch fire or bum on its own. It is so because a combustible substance does not catch fire as long as its temperature is lower than its ignition temperature.

Extra Question Of Class 8 Science Question 14.
Define spontaneous combustion.
Answer:
The type of combustion in which a material suddenly bursts into flames without the application of any apparent cause is called spontaneous combustion, e.g., combustion of coal dust.

Combustion And Flame Class 8 Pdf Download Question 15.
What causes fires in coal mine?
Answer:
Spontaneous ‘combustion of coal dust results in many disastrous fires in coal mines.

Class 8 Science Chapter 6 Question Answer Question 16.
What leads to deforestation? What is its effect?
Answer:
Cutting of trees leads to deforestation. It is quite harmful as it leads to global warming.

Question 17.
Is there any ideal fuel? If not, what is the alternative?
Answer:
There is probably no fuel that could be considered as an ideal fuel. We should, as an alternative, look for a fuel which fulfils most of the requirements for a particular use.

Question 18.
What is global warming? What causes it?
Answer:
The increase in temperature of earth’s atmosphere is termed as global warming.
The excess increase of carbon dioxide in atmosphere causes global warming because carbon dioxide facilitates greenhouse effect, i.e., carbon dioxide traps hot radiations emitted by the earth’s surface.

Question 19.
What is done to extinguish fire due to burning of oil or petrol?
Answer:
Fire produced by burning of oil or petrol can be controlled by throwing sand or soil over it.

Question 20.
What is flame?
Answer:
When a fuel is burned, a hot luminous gas emerges out of the burning fuel. This gas is called flame. Flames are a result of the substances which vaporize on burning. Example includes kerosene oil, wax, etc. which form flames on burning.

Question 21.
Explain greenhouse effect. Mention any two greenhouse gases.
Answer:
Greenhouse effect is warming of earth’s surface and atmosphere due to trapping of sun’s heat by certain gases in the earth’s atmosphere. Water vapour, carbon dioxide, methane and certain other gases in the air are responsible for the Greenhouse effect of those gases, water vapour has the largest effect.

Question 22.
What is the role of water in extinguishing fire?
Answer:
Water cools the combustible material, so that its temperature is brought below its ignition temperature. This prevents the fire from spreading. Water vapours also surround the combustible materials helping in cutting the supply of air. So, the fire is extinguished.

Question 23.
Why can we not use water to extinguish fire that is caused due to burning of oil or petrol?
Answer:
When water is used to extinguish fire due to burning of oil/petrol, water being heavier than oil/petrol settles down below it and it continues to burn. That is why we cannot use water to extinguish fire in such a situation.

Question 24.
What would you do in case of fire produced by electric short circuit?
Answer:
In the case of fire caused by electric short circuit, water is not used at all because it is a conductor of electricity and may cause electrocution or electric shock. The only solution is to cut off the supply of electricity and then use the spray of water on the flame to extinguish fire or use fire extinguisher.

Question 25.
What is the working methodology of fire extinguisher?
Answer:
Fire extinguisher functions in one of the following ways :

1. either it cuts off supply of air to the combustible substance.
2. or it brings down the temperature of the combustible substances well below its ignition temperature.

Question 26.
What are the causes of forest fires? How can it be kept under control?
Answer:
Forest fires sometimes occur due to the heat of the sun. However, most forest fires are due to the carelessness of human beings. So, it is important to remember that the campfires must be completely extinguished before leaving a forest after a picnic or any visit and people should not throw any burning thing in the forest.

Question 27.
What do you mean by explosion? How does it take place?
Answer:
Explosion is a sudden reaction in which heat, light, sound and large amount of gas is evolved. Explosion can also take place if pressure is applied on the cracker or any other combustible material kept in large amount.

Question 28.
What are the characteristics of an ideal fuel?
Answer:
The characteristics of an ideal fuel are:

• It should be readily available,
• It should be cheap,
• It should bum easily in air at a moderate rate,
• It should produce a large amount of heat, and
• It should not leave behind any undesirable substances.

Question 29.
What are the disadvantages of burning wood in a chulha?
Answer:
Disadvantages of burning wood in a chulha are :

• It produces a lot of smoke, which causes respiratory problems.
• Burning of wood leaves behind ashes, which are undesirable substances.
• Cutting of wood for fuel leads to deforestation.

Question 30.
What are the disadvantages of global warming?
Answer:
Global warming causes the rise in temperature of the atmosphere of the earth. This leads to melting of polar glaciers resulting into rise in sea level and causing floods in the coastal areas.

Question 31.
What is the function of a fire extinguisher? Describe various types of fire extinguishers.
Answer:
Fire extinguishers either cut off supply of air to the combustible substance or it brings down the temperature of the combustible substance well below its ignition temperature.

There are various types of fire extinguishers used for controlling fire :

• Soda acid fire extinguishers: It is based on the principle of cooling the fire. Carbon dioxide is liberated along with water. Water puts off the fire by lowering the temperature of the combustible material below its ignition temperature and carbon dioxide cuts off the supply of air to the combustible substances.
• Hydrocarbon fire extinguishers: It is based on the principle of covering burning material and cut off of oxygen supply to the fire. In this fire extinguisher, sodium bicarbonate comes out under pressure in the form of a foam. The foam covers the whole surface of oil. It cuts off the supply of air and the fire is controlled.

Question 32.
What are the harmful effects of fuel consumption on the environment? Describe.
Answer:
The increasing fuel consumption has the following harmful effects on the environment.

• Carbon fuels like wood, coal, petroleum release unburnt, carbon particles. These particles are dangerous pollutants causing respiratory diseases, such as asthma.
• Incomplete combustion (combustion in insufficient supply of oxygen or air) forms carbon monoxide gas. It is a very poisonous gas.
• Combustion of most fuels releases carbon dioxide in the environment. Increased percentage of carbon dioxide in the air is believed to cause global warming.
• Burning of coal and diesel releases sulphur dioxide gas. It is an extremely Suffocating and corrosive gas.
• Petrol engines are responsible for the formation of nitrogen oxide gas.

Multiple Choice Questions (MCQs)

1. From the following the ideal fuel is
(a) Wood
(b) Coal
(c) CNG
Answer:
(c) CNG.

Extra Questions for Class 8 Science

Here we are providing Online Education for Cell Structure and Functions Class 8 Extra Questions and Answers Science Chapter 8 was designed by subject expert teachers. https://ncertmcq.com/extra-questions-for-class-8-science/

Online Education for Class 8 Science Chapter 8 Extra Questions and Answers Cell Structure and Functions

Class 8 Science Chapter 8 Extra Questions Question 1.
List some of the basic functions carried out by all living organisms.
Answer:
Growth and development, movement, digestion, respiration, excretion, reproduction, etc.

Cell Structure And Function Class 8 Extra Questions Question 2.
What is a cork?
Answer:
Cork is a part of the bark of a tree.

Class 8 Science Ch 8 Extra Questions Question 3.
What is meant by cell in Latin?
Answer:
Cell in Latin means “hollow space”.

Cell Class 8 Extra Questions Question 4.
What instrument helped in studying the living cells?
Answer:
Microscopes helped in studying the living cells.

Class 8 Science Chapter 8 Extra Questions And Answers Question 5.
How many cells are there in a human body? What about their shape and size?
Answer:
Human body has trillions of cells, which vary in shape and size on the basis of their functions.

Class 8 Science Chapter Cell Structure And Function Extra Questions Question 6.
What is the name of organism made of more than one cell?
Answer:
They are called multicellular.

Cell Structure And Function Class 8 Extra Questions And Answers Question 7.
What is meant by unicellular organisms?
Answer:
The single-celled organisms are called unicellular organisms, (uni = one, cellular = cell).

Class 8 Chapter 8 Science Extra Questions Question 8.
What is the size of cell of a bacteria ?
Answer:
0.1 to 0.5 micrometre (mm).

Cell Structure And Function Extra Question Answer Question 9.
What is tissue?
Answer:
Tissue is a group of similar cells performing a specific function.

Cell Structure And Function Class 8 Questions Question 10.
Is cell wall present or absent in animal cell?
Answer:
It is absent.

Class 8 Cell Extra Questions Question 11.
When can chromosomes be seen?
Answer:
The chromosomes can be seen only when the cell divides.

Chapter 8 Science Class 8 Extra Questions Question 12.
Name two organisms which are made of single cell.
Answer:
Amoeba and Paramecium.

Class 8 Science Cell Structure And Function Extra Questions Question 13.
When you cut your hair and nail, you do not feel pain. Why?
Answer:
When nail and hair are cut, we do not feel any pain because the cells of nails and hair are dead cells.

Class 8 Cell Structure And Function Questions Question 14.
Why are we able to know a lot about cell structure today?
Answer:
Today, we know a lot about cell- structure and its functions because of the improved microscopes having higher magnification.

Class 8th Science Chapter 8 Extra Questions Question 15.
How are cells in the living organisms arranged?
Answer:
The cells in the living organisms are arranged in the similar manner as bricks are arranged to make a building.

Extra Questions Of Chapter 8 Class 8 Science Question 16.
What are basic structural units in buildings and living organisms?
Answer:
Bricks in buildings and cells in the living organisms are the basic structural units.

Ch 8 Science Class 8 Extra Questions Question 17.
Does egg of a hen represent a single cell?
Answer:
Yes, egg of a hen represents a single cell and is big enough to be seen by unaided eye.

Extra Questions On Cell Structure And Formation Class 8 Science Question 18.
While studying living cells with microscope, why do we use stains?
Answer:
Stains (dyes) are used to colour the parts of the cell to observe and study their detailed structure clearly under microscope.

Cell Class 8 Important Questions Question 19.
What is the difference between the functions of organisms with one cell and the organisms with multi cells?
Answer:
A single-celled organism captures and digests food, respires, excretes, grows and reproduces with its single cell. Similar functions in multicellular organisms are carried out by groups of specialised cells forming different tissues which in turn form organs.

Extra Questions For Class 8 Science Chapter 8 Question 20.
What are the projections in Amoeba called? What do they do?
Answer:
The projections in Amoeba are known as pseudopodia (pseudo = false; podia = feet). These projections are in fact false feet and these appear and disappear as Amoeba moves or feeds.

Question 21.
What is the size of cells in living organisms?
Answer:
The size of cells in living organisms may be as small as a millionth of a metre or a few centimetres. However, most of the cells are microscopic in size and are not visible to the unaided eye.

Question 22.
What is the size of smallest cell? What is the size of red blood cells (RBCs) found in the human body?
Answer:
The size of the smallest cell is 0.1 to 0.5 micrometre (pm) found in bacteria and that of red blood cells in the human body measure seven micrometre.

Question 23.
Give example of a large cell. State the size of the largest cell.
Answer:
The hen’s egg is an example of large. cell, which is quite large that it can be seen by an unaided eye. The largest cell, measuring 170 x 130 mm, is the egg of an ostrich.

Question 24.
What are white and yellow parts of an egg called?
Answer:
In an egg, a white material surrounds the yellow part. The white material is called albumin, and the yellow component is called yolk.

Question 25.
Define the terms: tissue and organ.
Answer:
Tissue: A tissue is a group of similar cells performing a specific function.
Organ: It is a group of tissues performing a specific function.

Question 26.
Define nucleus. What is its role?
Answer:
The central dense round body in the centre of the cell is called nucleus. In addition to its role in inheritance, nucleus acts as control centre of the activities of the cell.

Question 27.
Define the term cytoplasm.
Answer:
The jelly-like substance found between the nucleus and the cell membrane is called cytoplasm.

Question 28.
How do we observe the cell by microscope?
Answer:
To observe the cell by microscope, sometimes an organ has to be cut into sections to observe various smaller components. Some components in these sections are visible through the microscope after staining (dying) with coloured dyes.

Question 29.
What was the observation of a part of the bark of a tree (cork) by Robert Hooke?
Answer:
Robert Hooke in 1665 observed slices of cork under a simple magnifying device. He took thin slices of cork and observed them under a microscope. He noticed partitioned boxes or compartments in the cork slice. These boxes appeared like a honeycomb. He coined the term cell for each box.

Question 30.
Describe the differences and similarities between cell and brick.
Answer:
The cells in the living organisms are arranged and appear like bricks in a building. Both bricks in the building and cells in the living organisms are basic structural units. The buildings, though built of similar bricks, have different designs, shapes and sizes. Similarly, in the living world, organisms differ from one another but all are made up of cells. But, cells in the living organisms are complex living structures, unlike non-living bricks.

Question 31.
Which part of the cell gives shape to it?
Answer:
Components of cells are enclosed in a membrane called cell membrane. This membrane provides shape to the cells in plants and animals. Cell wall is an additional covering over the cell membrane in plant cells. It gives shape and rigidity.

Question 32.
Is there any relation between the size of the body of the animal or plant with the size of the cell?
Answer:
The size of the cell, in fact, has no relation with the size of the body of the animal or plant. The size of the cell is related to its function. For example, nerve cells, both in the elephant and rat, are long and branched. They perform the same function of transferring messages in bigger as well as in the smaller organism.

Question 33.
How do cells/groups of cells perform different functions in multicellular organisms?
Answer:
The cell in a living organise is the basic structural unit. Cells combine to form tissues and a group of tissues is called an organ. These organs together constitute different systems in living beings and perform different functions. Each organ in the system performs different functions.

Question 34.
What constitutes cytoplasm?
Answer:
Cytoplasm is a fluid present between the cell membrane and the nucleus and is made up of basic elements like carbon (C), hydrogen (H), oxygen (O) and nitrogen (N). These are found in the form of chemical substances like carbohydrates, proteins and water.

Question 35.
What are the components present in cytoplasm?
Answer:
Besides nucleus, various other components or organelles of cells are present in the cytoplasm. These are mitochondria, Golgi bodies, ribosomes, etc. Cytoplasm, along with nucleus, forms the living substance of a cell. This living substance is called protoplasm.

Question 36.
What is nucleolus? Describe its function in brief.
Answer:
Nucleolus is a small, spherical, dense body in the nucleus. The function of nucleolus is to assemble ribosomes.

Question 37.
What are prokaryotic cells and eukaryotic cells?
Answer:
The cells having nuclear material without nuclear membrane are termed prokaryotic cells. The organisms with these kinds of cells are called prokaryotes (pro = primitive; karyon = nucleus). Examples are bacteria and blue-green algae.
The cells having a well-organised nucleus with a nuclear membrane are designated as eukaryotic cells. The organisms having these cells are called eukaryotes (EU = true; karyon = nucleus). Examples are onion, cells and cheek cells.

Question 38.
What is the function of nucleoplasm?
Answer:
Nucleoplasm of nucleus contains thread-like structures called chromosomes. These carry genes and help in inheritance.

Question 39.
Define the function of following:
(a) Plasma membrane
(b) Mitochondria
(c) Gene
(d) Vacuole
(e) Plastid
Answer:
(a) Plasma membrane: It is the outer covering of the cell which separates its contents from the surrounding medium. It is made up of lipids and protein. The main function of cell membrane is to regulate the movement of molecules in and out of the cell.

(b) Mitochondria: Mitochondria are the powerhouses of the cell because energy is released from the mitochondria after respiration. They are the sites cellular respiration of or oxidation of food.

(c) Gene: Genes carry information of heredity help in inheritance or transfer of characters from the parents to the offspring.

(d) Vacuoles: Cells contain water-filled, sac-like structures called as vacuoles. They are large-sized in plant cells while either absent or small-sized in animal cells.

(e) Plastids: The coloured bodies in the cytoplasm of the cells are called plastids. Plastids are found in plant cells only. Chloroplast i.e., the green plastids contains chlorophyll for the process of photosynthesis. Through this process, plant cell prepares food which is ultimately stored in the form of starch.

Question 40.
What are the basic components of a cell? Describe their functions.
Answer:
The basic components of a cell are :
(i) Cell membrane
(ii) Cytoplasm
(iii) Nucleus

(i) Cell membrane separates the inside contents of the cell from outside. It being porous, allows movement of substances or materials both inwards and outwards of the cell.

(ii) Cytoplasm contains the cell organelle, which performs different functions.

(iii) Nucleus acts as a control centre of a cell. In addition to it, it also facilitates inheritance.

Multiple Choice Questions (MCQs)

1. The longest cell in human being is
(a) blood cell
(b) nerve cell
(c) cheek cell
Answer:
(b) nerve cell.

2. The cells having nuclear material without nuclear membrane are called :
(a) Eukaryotic cell
(b) Prokaryotic cell
(c) Eukaryotic cord.
Answer:
(a) Eukaryotic cell.

3. The change of shape of Amoeba is due to:
(a) Cell
(b) Pseudopodia
(c) None of these
Answer:
(b) Pseudopodia.

Extra Questions for Class 8 Science