Question

The current generator Ig' shown in figure, sends a constant current i through the circuit. The wire ab has a length l and mass m and can slide on the smooth, horizontal rails connected to Ig. The entire system lies in a vertical magnetic field B. Find the velocity of the wire as a function of time.
Figure

Answer 1

EMF is Product of Speed, Length and Field

Explanation:

Electromotive Force on the wire, EMF = iℓB  

Acceleration (Velocity Per Unit TIme)= $\frac {i\rho B}{m}$  

Velocity (Length of Circuit per unit time) = $\frac {i\rho Bt}{m}$