Question

In zero gravity region, a point charge +Q of mass M is connected to a spring of natural length L0 and spring constant k. A uniform magnetic field B is directed inside the plane of paper. The point charge is given an initial velocity v0 perpendicular to the length of spring as shown. It is given that B=Mv0QL0. Then which of the following quantities remain(s) conserved during the motion of particle ?

Answer 1

Answer:

abcd

Explanation:

Magnetic force = BQVO=MV0/QLO x V0 x Q0=mvO^2/L0

Which is equal to centripetal force so block is circular motion about O and radius

L0.

So, spring forces is zero. So potential energy is constant. Magnetic force will not

do work, so kinetic energy is constant.