Objective questions of of chapter-3(force) of class -6.

 A. Objective questions:

1. Write true or false for each statement:

a) The frictional force acts in the direction of motion of body.

Ans. False.

The frictional force acts in the direction opposite to the direction of motion of body.

b) The unit of weight is kilogram.

Ans. False.

The unit of mass is kilogram. Or

The unit of weight  is Newton.

c) air force can change the direction of motion of a moving body.

Ans. True.

d) A force increases the mass of the body when applied on it.

Ans. False.

A force does not affect the mass of the body when applied on it.          Or

A mass of a body is constant irrespective of force applied on it.

e) The force of friction is always disadvantageous.

Ans. False.

The force of friction is sometime advantageous as well as disadvantageous for us.

f) The sliding friction is more than the rolling friction.

Ans. True.

g) liquids offer more friction than the gases.

Ans. True.

h) A wet oily road offers more friction than a dry rough road.

Ans. False.

A wet oily road offers less friction than a dry rough road.

2. Fill in the blanks:

a) force is applied as.. push.... or .... Pull.....

b) on squeezing a gum tube, its... Shape... Changes.

c) on pulling a string, its.. length... Increases.

d) a moving football when kicked, its .... Direction of motion or. Speed..changes.

e) on applying brakes on a moving car, speed.. decreases.or. Slows down.

f) we use ball bearings to. Reduce... the Friction.

g) friction... Opposes... the motion.

h) lubricants are used to.. reduce..... Friction.

I) friction causes. Wear and tear..... Of moving parts of a machine.

3. Match the following columns:

a) Non-contact force.  - gravitational force

b) like poles- repel

c) contact force- force of friction

d) mass- kg

e) weight- kgf

f) friction- wear and tear.

4. Select the correct alternative:

a) a body falls downwards because of

•electrical force

•gravitational force.

•mechanical force

•magnetic force

b) A force does not change

•mass

•length

•shape

•state of motion

c) a force to be expressed correctly requires

•only the magnitude

•only the direction

•both the magnitude and direction

•none of the above

d) friction

•promotes motion

• opposes motion

•acts in the direction of motion

•is always a nuisance

e) friction is reduced by

•making the surfaces wet

••making the surfaces dry

•making surfaces  rough

•sprinkling sand on the surface.

f) friction

•causes wear and tear

•produces heat

•stops a moving body

•has all the above disadvantages.

g) friction is increased if

•an oil is sprayed

•the surfaces are made wet.

•the surfaces are made dry.

•the surfaces are polished.