A player with 3 m long iron rod runs towards east with a speed of 30 km/hr. Horizontal component of earth's magnetic field is  4×10−5Wb/m2. If he is running with rod in horizontal and vertical positions, then the potential difference induced between the two ends of the rod in two cases will be

If player is running with rod in vertical position towards east, then rod cuts the magnetic field of earth perpendicularly (magnetic field of earth is south to north).Hence Maximum emf induced is  e=Bvl=4×10−5×30×10003600×3=1×10−3voltWhen he is running with rod in horizontal position, no field is cut by the rod, so e = 0.