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Let’s
Revise

Ÿ A simple machine is simple tool we use to make our work easier.
Ÿ Machines help us to do work with less effort.
Ÿ There are mainly six types of simple machines namely: Lever, Pulley, Inclined Plane,

Wedge, Screw and Wheel and Axle.
Ÿ Complex machines are formed when two or more simple machines are joined together.

Points to Remember

Lever : A rod or a board fixed at a point called fulcrum

Inclined plane : A flat surface with one end higher than the other

Pulley : Simple machine made of rope and a wheel

Wheel and axle : A wheel attached to a rod

Wedge : A simple machine made up of two inclined planes

Complex machines : Machines made up of one or more simple machines

E XE R C I S E

A. Tick (ü) the correct answer.
1. Simple machines are the simple/complex tools.
2. Scissors/ cranes are the good example of lever.
3. Inclined plane/Lever is a flat surface with one end higher than the other.
4. Pulley is made of wheel and rope/rod.
5. Complex/Simple machines are formed when two or more simple machines
are joined together.

B. Complete the sentences given below.
1. ......................... make our work easy.
2. There are mainly ...................... simple machines.
3. A .................is a simple machine made up of a wheel and a rope.
4 . The ..................... is simply a ramp or flat, sloping surface.
5. A wheel and axle has .....................parts to it.

C. Tick (ü) for the correct and (û) cross for the wrong statements.
1. A hammer is an example of lever.
2. Simple machines make our work hard.

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