Tag: friction

Quizzes (10) Questions (79)

Questions Related to friction

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

The force which prevents us from slipping while walking on the road is:

  1. muscular force of our body

  2. gravitational pull by earth

  3. frictional force

  4. balanced forces of nature
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When we push the ground with our feet, the friction provides a forward reaction to our push and sends us forward. Walking on smooth ground is difficult because the frictional force is not great enough to prevent slipping.


Option C is correct.

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

In which of the following cases more friction is desirable?

  1. Movement of piston in a cylinder

  2. Braking of a vehicle

  3. Running on a track

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B.

Brakes is a type of automotive brake that slows or stops a vehicle by converting kinetic energy into heat energy, via friction. The heat energy is then dissipated into the atmosphere. 
Hence, braking of a vehicle happens due to friction.

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

The surface of the head of a matchstick and sides of a match box are deliberately made rough to

  1. Increase friction

  2. Decrease friction

  3. Increase pressure

  4. Decrease amount of heat
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A.

A match is a small stick of wood or strip of cardboard with a solidified mixture of flammable chemicals deposited on one end. When that end is struck on a rough surface, the friction generates enough heat to ignite the chemicals and produce a small flame. Some matches, called strike-anywhere matches, may be ignited by striking them on any rough surface.
Hence, the surface of the head of a matchstick and sides of a match box are deliberately made rough to increase friction.

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

Friction reduces efficiency of machines due to:

  1. Production of heat

  2. Wearing out of moving parts

  3. Increase in energy consumption

  4. AlI of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Answer is D.

Efficiency is relate to energy conversion performance. A system that can convert energy entirely and completely into energy of another form performs the conversion at 100% efficiency. 
The heat produced by friction cannot be used to recover 100% of the mechanical energy that was converted into heat, the effect of friction is to reduce the (energy conversion) efficiency of machines. 
The parts of the machine wear and tear due to contimuous usage.
More the friction more the enrgy consumption.
Hence, all the options are correct.

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

_______ is responsible for wear and tear of machine parts.

  1. Oil

  2. Steel

  3. Friction

  4. Smoothness
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Friction is responsible for wear and tear of machine parts.
Friction is the main force that is responsible for the wear and tear of machinery, this is why mechanical parts are sometimes oiled, to minimize the friction present.

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

You are marooned on a frictionless horizontal surface and cannot exert any horizontal force by pushing against the surface. How can you get off?

  1. By jumping

  2. By spitting or sneezing

  3. By rolling your body on the surface

  4. By running on the plane
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We will need friction to roll or run on any surface. In our case, we have a frictionless surface. Hence, by conservation of linear momentum sneezing can make us move on that surface.