A metallic cube of side 15 cm moving along y-axis at a uniform velocity of 2ms−1. In a region of uniform magnetic field of magnitude 0.5 T directed along z-axis. In equilibrium the potential difference between the faces of higher and lower potential developed because of the motion through the field will be ____ mV.
Answer: 150
Solution
The motional emf induced across the cube is given by ΔV=(v×B)⋅d. With v=2 m/s along y-axis, B=0.5 T along z-axis, and the cube side d=0.15 m along x-axis, we get ΔV=vBd=2×0.5×0.15=0.15 V =150 mV.