Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectromagnetic Induction
A rod of length l is rotating at a uniform angular velocity about its perpendicular bisector. A uniform magnetic field B is present parallel to the rotation axis. The potential difference between the two ends of the rod is
Options
- Azero
- B1 2 B l ^2
- CB l ^2
- D2 B l ^2
Correct answer
A. zero
Step-by-step solution
Let the center of the rod be O and its two ends be A and B . The rod rotates about its perpendicular bisector, so the distance of both ends from the axis of rotation is l/2 . The motional emf induced between the center O and end A is given by: V_A - V_O = 1 2 B ( l 2 )^2 = 1 8 B l^2 Similarly, the motional emf induced between the center O and end B is: V_B - V_O = 1 2 B ( l 2 )^2 = 1 8 B l^2 The potential difference between the two ends A and B is: V_A - V_B = (V_A - V_O) - (V_B - V_O) = 0 Alternatively, the induce