1. It is difficult to walk on any oily floor because
Correct : D. Force of friction is very less
2. Spring balance is a device used for measuring the _____________ acting on an object.
Correct : C. force
3. A matchstick struck on a matchbox catches fire easily because
Correct : A. Friction may cause fire
4. Tyres are treaded to
Correct : B. Increase friction
5. Lubricants are substances which
Correct : C. Reduces friction
6. Sliding friction is _________ than / to rolling friction
Correct : A. smaller
7. The frictional force exerted by fluids is also called ______
Correct : B. drag
8. Four children were asked to arrange forces due to rolling, static and sliding frictions in a increasing order. Their arrangements are given below. Choose the correct arrangement.
Correct : C. Rolling, sliding, static
9. A boat or an aeroplane has a pointed or tapering front / head. Why?
Correct : B. To reduce the friction of fluid
10. The sole of the shoes becomes plain after wearing it for several months. The reason is