Coal and Petroleum - Exemplar Solutions 1

CBSE Class 8 Science
NCERT Exemplar Solutions
CHAPTER 5
Coal and Petroleum

MULTIPLE CHOICE QUESTIONS

1. Various materials which are obtained from nature are called natural resources. Which of the following is not a natural resource?

(a) minerals

(b) water

(d) plastic

Ans. (d) plastic is not a natural resource since it cannot be found naturally in our environment and it is only processed from natural resource.

2. Air is a natural resource and cannot be exhausted by human activities. It is known as inexhaustible natural resource. Which of the following is another inexhaustible natural resource?

(a) coal

(b) petroleum

(d) minerals

Ans. (c) Inexhaustible natural resources are not going to get exhausted by human activities because these resources are available in an unlimited quantity in nature as they get renewed naturally in a very short span of time. Sunlight is available in an abundant quantity and gets renewed automatically. Therefore, this resource is not going to exhaust.

3. Which of the following is a pair of exhaustible natural resources.

(a) coal and soil

(b) air and sun-light

(d) wild life and minerals

Ans. (d) wild life and minerals are a pair of exhaustible natural resources. If it is used in excess quantity can get exhausted as it taken a long time for them to get renewed.

4. Coal is processed in industries to get some useful products. Which of the following is not obtained from coal?

(a) coke

(b) coal tar

(d) CNG

Ans. (d) Natural gas is stored under high pressure in the form of compressed natural gas (CNG). Coke, coaltar and coal gas are obtained from coal.

5. Exhaustible natural resources are:

(a) unlimited in quantity.

(b) not dependent on nature.

(d) not exhausted by human activities.

Ans. (c) Exhaustible resources are present in limited quantity in nature and hence are susceptible to get exhausted as a result of excessive use.

6. Fossil fuels are obtained from:

(a) remains of non-living materials.

(b) dead remains of birds only.

(d) dead remains of living organisms.

Ans. (d) Fossil fuel are produced from remains of dead pants and animals under some thousand feet of deposit. With time, they get decayed and under high heat and pressure and after millions of years they get converted to Petroleum or crude oil, coal, natural gas deep inside the earth’s crust. Hence, they are also known as non-renewable energy sources as they take huge time span to get renewed.

7. Coal is formed from the remains of

(a) vegetation only

(b) animals only

(d) neither vegetation nor animals

Ans. (a) Long time back due to natural calamity like flooding earthquakes, etc. the thick forest cover get buried down underneath the soil. With time, they got compressed as more soil deposited over them. As they descended deeper and deeper they encountered high temperature and pressure and slowly got converted to coal.

8. Which substance is formed by the carbonisation of dead vegetation?

(a) coal

(b) coke

(d) coal tar

Ans. (a) The main constituent of coal is carbon therefore this process of conversion of dead plants into coal is termed as carbonization.

9. Naphthalene balls are obtained from coal tar and are used as

(a) mosquito repellant

(b) honey bee repellant

(d) snake repellant

Ans. (c) Naphthalene balls are obtained from coal tar and are used as moth repellent.

10. Which of the following is not a constituent of petroleum?

(a) paraffin wax

(b) lubricating oil

(d) coke

Ans. (d) coke is a hard, black coloured and porous derivative of coal.

11. Petroleum was formed from organisms:

(a) living on the land

(b) living on the plants

(d) living on the rocks

Ans. (c) Long time back plants and animal inside the sea died and their bodies settled down at the bottom surface of the sea and slowly got buried, down underneath the soil. With time they got compressed as more layers of sand clay deposited over them. As they descended deeper and deeper under high temperature and pressure along with the absence of air these dead plants and animals slowly got converted to petroleum and natural gas.

12. 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.

(d) Natural gas cannot be used for power generation.

Ans. (c) Natural gas is stored under high pressure as compressed natural gas.