General Science 6th Class Chapter 8 Energy Solved Exercise

General Science

6th Class

Chapter 8

Energy

Questions

8.1 Encircle the correct option.

1. Temperature of an object is the measure of _________ of its particles:

a. gravitational potential energy        b. strain energy

c. kinetic energy        d. sound energy

2. When we drill a hole in an object, which of the following forms of kinetic energy is useful to us?

a. sound        b. heat        c. light        d. mechanical energy

3. Our food is a source of:

a. mechanical energy        b. chemical energy        c. sound energy        d. electrical energy

4. An example of renewable energy sources:

a. coal        b. natural gas        c. wind        d. petrol

5. During work done, energy is:

a. produced        b. destroyed        c. wasted        d. converted into other form

6. Which of the following is not an energy converter?

a. table        b. radio        c. fan        d. room heater

7. A fruit after its detachment from a tree-stalk begins to convert energy due to its position into:

a. strain energy        b. kinetic energy        c. chemical energy        d. electrical energy

8. The mixture of gases formed by the decay of animals wastes:

a. greenhouse gas        b. biogas        c. natural gas        d. water gas

9. Engine of a vehicle starts working using:

a. electrical energy        b. light energy        c. heat energy        d. sound energy

10. During an energy conversion, the total amount of energy:

a. destroys        b. decreases        c. increases        d. remains the same

8.2 Write short answer.

1. Name three forms of stored energy.

Ans.

i. Elastic potential energy.

ii. Energy stored in food, batteries, biomass and fossil fuels, etc. is chemical energy.

iii. Gravitational potential energy.

2. Dissipated energy is also called wasted energy. Why?

Ans.

When energy is converted to a form of energy useful to us, many other forms of energy that are not useful to us may be produced and spread out. This spreading out energy into different forms is called dissipation of energy. The dissipated forms of energy are wasted. Hence, the dissipated energy is also called wasted energy.

Example: When we switch on the electric bulb, light is useful to us, but the heat produced by glowing bulb is wasted and thus called dissipated energy.

3. Define the law of conservation of energy.

Ans.

"Energy can neither be created nor be destroyed, but, it can be changed from one form to another" This fact is known as law of law of conservation of energy.

4. Where does the energy produced by a dynamo come from?

Ans.

A dynamo is a device typically located in the hub of a bicycle's wheel that converts the energy generated by the wheel spinning to electrical energy. That energy is then used to run front and rear dynamo lights on the bicycle.