In what ways is friction harmful?
A. It causes wear and tear to the surfaces.
B. Much energy is lost in overcoming friction.
C. Both A and B
D. None of these

Hint: Friction is a resistive force which comes into the picture when there is contact of the two irregular surfaces. This creates the rubbing of the two surfaces. So, it can hinder the motion of a body and cause the need for expending extra energy.

Complete answer:
When the two surfaces come in contact and start rubbing and friction force makes this rubbing possible then there is a chance that the rubbing surfaces get damaged over the period of time. Hence, they will go under wear and tear.

Example of the wear and tear (effects harmful of the friction)-
When the soles of shoes rub against the rough surface of the road, then tiny pieces of the soles keep on breaking off slowly due to which the soles of our shoes wear out gradually. The wear and tear of the soles of our shoes ultimately causes holes in the soles.
Hence, the way in which friction is harmful that It causes wear and tear to the surfaces.

So, the correct answer is “Option A”.

Note:
Some more harmful effects of the friction is as following-
I)If there was no friction, cars would get much better gas mileage and almost without any loss of petrol or diesel but it would also lead to some serious accidents.
II)To overcome the force of friction a large amount of force has to be applied, so a lot of force is wasted on overcoming it.
III)Due to the friction the meshing surfaces of the devices heat up and due to heating the machines can be damaged.