Motional EMF
A metal rod of length 'L' completes the circuit as shown. The area of the circuit is perpendicular to magnetic field 'B'. Total resistance of the circuit is 'R'. The force needed to move the rod in the direction as shown with constant speed 'V' is

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Answer: (b)
- Emf , current .
- Opposing magnetic force .
- For constant speed, applied force . So the answer is (b).