Friction

Friction is a

• non-contact force

• contact force

• magnetic force

• electrostatic force

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

• only if the objects are solid.

• only if one of the two objects is liquid.

• only if one of the two objects is gaseous.

• irrespective of whether the objects are solid, liquid or gaseous.

To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?

• Stone

• Plastic block

• There is no need to sharpen a knife

• Glass block

It is difficult to walk on an oily floor because

• Floor gets spoiled

• Floor hates oil so it makes it difficult to walk on it until oil is removed

• Force of friction is high

• Force of friction is very less

Spring balance is a device used for measuring the _____________ acting on an object.

• number of molecules or atoms

• weight

• force

• food

A matchstick struck on a matchbox catches fire easily because

• Friction produces heat

• Of chemical reaction

• Matchstick is afraid of us

• Matchstick obeys us because we are their masters

The sole of the shoes becomes worn out after wearing it for several months. The reason is

• Wearing out due to friction

• No reason at all

• Sole is of bad quality

• Nature

The factors affecting friction are

• Dependence of friction on the nature of two surfaces

• Dependence of friction on the force with which two surfaces are pressed together

• Don't know

• Friction looks after and affects itself

What kind of substances are known as lubricants?(function)

• Increase friction

• Decrease friction

• Increase or decrease friction

• None of these

Friction has only disadvantages

• True

• False

• Don't ask me!!