A player with 3m long iron rod runs towards east with a speed of `30 km//h` Horizontal component of earth magnetic field is `4 times 10^-5 Wb//m^2` IF he is running with rod is horizontal and vertical positions, then the potential differences induced between the two ends of the rod in two cases will be:

Options

A. Zero in vertical position and `1 times 10^-3 V` in horizontal position
B. `1 times 10^-3V` in vertical positions and zero is horizontal positions
C. Zero in both cases
D. `1 times 10^-3 V` in both cases

Explanation

IF player is running with rod in vertical position towards east, then rod the magnetic field of earth perpendiculary (magnetic field of earth is south to north). Hence maximum emf induced is
`E=Bvl=4 times 10^-5 times (30 times 1000)/3600 times 3=1 times 10^-3 volt`
when he is running with rod in horizontal position, no field is cut by the rod, so E=0