2 AL Physics MC

These are MC from 03 AL physics past paper.

5. The answer is A.

Using energy conservation consideration, K.E. of the system + E.P.E. of the system = constant.

When the separation between P and Q is the smallest, the spring has a maximum compression.

Obviously, the speed of P will be decreasing in the process, while the speed of Q will be increasing.

So, there exists a particular moment that the speed of P and Q are the same, in which the separation is the smallest. (Just consider just before this moment, P is approaching Q. And just after this moment, P is leaving Q because speed of Q > P)

So, when the two blocks have the same velocity, the spring will have maximum compression.


32. The answer is A.

(1) The electric field in shell A must be zero. If not, current will flow in the metal shell. So, without any influence of electric field, the positive induced charges will distribute uniformly on the outer surface of the shell. This is correct.

(2) The negative charges will be induced in the inner surface of the shell A. So, electric field will be directed from B to the negative charges. So, this is wrong.

(3) The electric potential at the two surfaces must be the same. If not, there will be an electric field in shell A, which violates statement 1. So, this is wrong.