NCTB Class 7 Science Chapter 7 “The Use of Energy” Solution
Bangladesh Board Class 7 Science Solution Chapter 7 “The Use of Energy” Solution Exercises Question and Answer by Experienced Teacher.
NCTB Solution Class 7 Chapter 7 “The Use of Energy”:
| Board | NCTB Bangladesh Board |
| Class | 7 |
| Subject | Science |
| Chapter | Seven |
| Chapter Name | “The Use of Energy” |
Fill in the blanks:-
(1) ——- of work is called energy.
Ans:- Capability.
(2) Usually generator transforms ——- energy into electricity.
Ans:- Mechanical.
(3) Biogas is produced from —- and —– constituent.
Ans:- Plant fertilizer, Animal fertilizer.
Short answered question:-
(1) (1) Ans:- When someone does any work as quick as possible, it is called his/her power. But the capability of doing the work is called his/her energy.
(1) (2) Ans:- We cannot create new energy or cannot destroy the energy. We can just transform the energy remains unchanged after transformation.
(1) (3) Ans:- The reasons of energy crisis are-
(a) More energy id required to meet the demand of increasing population.
(b) Energy is being used for construction purpose and vehicle maintenance at a high rate.
(4) Ans:- we can get more energy from less quantity of element by using non-renewable energy. Non-renewable energy is not limited in source.
Multiple choice questions:-
(1) Which one is the source of non-renewable energy?
Ans:- (d) Coal.
(2) Sometimes Atish studies using a charger fan with light. In this regard he uses—
Ans:- (a) (i) And (ii) .
(3) Which is the correct energy transformation from weight lifting to keeping down.
Ans:- (b) Mechanical energy-> static energy ->Mechanical energy-> Sound energy.
(4) Which two of the energy are related to having food and listening music of the weight lifter?
Ans:- (c) Chemical and sound.
Creative questions:-
(1) (a) Ans:- The main source of energy is sun.
(1) (b) Ans:- Natural gas is non-renewable gas because it is a natural resource which we can not produce more than once.
(1) (c) Ans:- we can produce electricity from ebb and flow of water more energy can be produce by using water flow. In this regard the bridge made for resisting water flow develops road networking. We can transform the ebb and flow of water energy in electrical energy.
(1) (d) Ans:- The suitability of the energy used in Samiha’s village are—
(a) The source of this energy unlimited.
(b) This energy is always environment friendly.
(2) (a) Ans:- When someone does any work as soon as possible, it is called his/her power.
(2) (b) Ans:- The transformation of energy is very necessary. As energy transforms one state to another the amount of energy is always equal.
(2) (c) Ans:- The gas produced by stimulator is biogas. The experiment from cows, pigs and hens, crops and plants are moistly used as its source. It is a renewable energy.
(2) (d)Ans:- The activity of Mr. Mumin regarding energy conservation is important because it is renewable energy. We can reuse its sources in order to produce energy again. We have huge possibility in biogas production as it is easy to get its source and it is also environment friendly.
