A conductor of length I and mass m can slide without any friction along the two vertical conductors connected at the top through a capacitor (figure). A uniform magnetic field B is set up ⊥ to the plane of paper. The acceleration of the conductor

Let v be the velocity of conductor at any time, then induced emf:e = Blv       ...(i)Charge on capacitor: q = Ce = CBlvCurrent in circuit: I=dqdt=CBldvdtfor conductor: mg-IBl=mdvdt⇒mg-CB2l2dvdt=mdvdt⇒dvdt=mgm+CB2l2This is the acceleration of conductor which is constant.