Figure shows a metal rod PQ resting on the rails AB and positioned between the poles of a permanent magnet. The rails, the rod and the magnetic field are in three mutual perpendicular directions. A galvanometer G connects the rails through a switch K. Length of the rod = 15 cm, B = 0.50 T, resistance of the closed loop containing the rod = 180.0 $m\Omega$. Assume the field to be uniform.

The magnetic force experienced by the rod when K is closed will be:

$3.75 \times 10^{-2} N$

The correct answer is Option (4) → $3.75 \times 10^{-2} N$