Que 1:- True or False

1) The first tools used by humans made out of metal

Answer:- False  

2) The first metal to be discovered was copper.

Answer:- True.

3) One of the important inventions that contributed to the industrial revolution was the stea engine.

Answer:- True.

4) it was possible to mark tools hard enough to cut trees, after the metal bronze was discovered.

Answer:- False.

Que 2) Give one word for

1) A device that makes a task easier

Answer:- Machine

2) Production of goods especially in factories

Answer:- Industry.

3) A machine that produces electricity.

Answer:- Generator

4) Electricity produced by using the force of flowing water as in dams

Answer:- hydroelectricity.

Que 3) Answer in short

1) which was the first metal to  be discovered?

Answer:- Copper was the first metal to be discovered.

2) how did the discovery of copper benefit humans?

Answer :- The discovery of this metal helped in the making of stronger and sharper tools.

Que 4 Give reason

1) the discovery  of iron is considered to be very important in the history of humans

Answer:- Iron is a very hard metal . Thus this can be used to make strong tools and weapons.

2) During the Industrial revolution cities became bigger.

Answer:- People from villages and nearby areas settles down in the cities to work in these factories. So, cities became larger and more populated.

Que :- Answer in brief

1) What is hydroelectricity ? what force is used to generate hydroelectricity?


  1.  Hydroelectricity in the generation of electricity from water.
  2.  The force of flowing water in rivers is controlled
  3. And is made use to generate this kind of electricity.

2) What are the problems in using fuels such as coal and petroleum as sources of energy ? How can these problems be solved ?


  • Coal and petroleum ate fuels thar are commonly used to day
  • But burning these fuels leads to pollution of air, water and land.
  • Alternate fuel like solar energy, wind energy and energy from water which do not pollute the environment.

Que:- Answer in detail. 

1) what do you mean by Industrial Revolution?


  • Earlier goods were made by hand by the people in their houses, using simple tools.
  • With the invention of the large steam driven machines, goods could be produced in large quantities with cheaper prices and letter qualities.
  • This led to the beginning of the big factory system using larger machines.
  • Lots of people from villages came to working these factories and the cities grew larger.
  • The significant changed from hand made goods to machine made goods.
  • This is known as the industrial Revolution.

2) what was the effect of the discovery f the steam engine on the industry at that time?


  •  Steam engine helped to run big machines.
  • So, more and more factories came up.
  • This helped in making more goods at much cheaper price.
  • Till about 300 years ago, people used to power of their own muscles and animals. 
  • Ans they also used the force of wind and flowing water to do all the work.
  • With the invention of the steam engine, they had a powerful force to run their machines.

Que :- 1) Short note

Iron :-

  • This was an important discovery as iron was harder than copper and bronze.
  • It was used to make much better tools and weapons
  • Iron tools were used to cut down trees and clear forest for agriculture.
  • Iron weapons made easier to hunt animals.
  • The discovery of iron helped humans progress faster.

Que:-  Define

1) Coal:-

Coal is obtained from mines and is also used in power plants to produce electricity.

2) Petroleum :-

This source of energy is found inside the earth we get fuels such as petrol , kerosene and diesel from it.