friction class 8

friction is a _________ force

• Non contact

• Contact

• magnetic

• electrostatic

Friction always

• Helps in motion

• Opposes motion

• Both of these

• None of these

Which of the following produces least friction?

• Rolling Friction

• Sliding Friction

• Static Friction

Whenever the surfaces in contact tend to move with respect to each other , the force of friction comes into play

• only if one of the two objects is liquid

• only if the objects are solid

• only if one of the two objects is gas

• Irrespective of whether the objects are solid,liquid or gas.

The shape of an aeroplane is like a _______ to reduce the friction exerted by air.

• Tortoise

• Dog

• Cat

• Bird

Friction produced due to fluids is called

• Sliding Fiction

• Rolling friction

• Static friction

• Drag

Which of the following is having least smooth surface comparatively ?

• Surface of wet soap

• Surface of mirror

• Surface of sole of new shoes

• Surface of granite

Force of friction depends on

• smoothness of surface

• area of contact of 2 objects

• inclination of surface

• All of these

Which is a/ are streamlined object?

• Aeroplane

• Boat

• Ship

• All the above

It is difficult to walk on an oily floor because

• Force of friction is very less

• Force of friction is very high

• we don't like to walk on oily floor

• None of these