JEE Mains Model Paper 12

A conducting rod PQ of mass m and of length l is placed on two long parallel (smooth and conducting) rails connected to a capacitor as shown below. The rod PQ is connected to a non-conducting spring of spring constant k, which is initially in relaxedstate. The entire arrangement is placed in a magnetic field perpendicular to the plane of the figure

Neglect the resistance of rails and rod. Now the rod is imparted a velocity v0 towards right.Then acceleration of the rod as a function of its displacement x is given by ….