JEE Plances Class Answered

Option A is correct . Because the value of P1 is equal to minimum friction force and the body will have tendency to go down the incline so the friction force will act opposite to the relative motion in upward direction of plane and this direction is taken as positive so friction would be maximum here.

But when P2 is applied the friction will act downward the incline which is limiting friction and the direction of friction will be taken as negative.