CUET and UG exam CUET UG 2025 Mock Test Series Physics Electromagnetic Induction and Inductance Induced Electric Fields
Comprehension Passage
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 mΩ. Assume the field to be uniform.
The power required (by an external agent) to keep the rod moving at the same speed (= 12 cms-1) when K is closed will:
1
Zero
2
9 × 10-3 W
3
4.5 × 10-4 W
4
6.4 × 10-3 W