A rectangular coil of 50 turns, area 0.02 m², rotates at 10 Hz in a uniform magnetic field of 0.5 T. The maximum induced emf is:
Correct answer: B. 31.4 V
- A. 15.7 V
- B. 31.4 V
- C. 62.8 V
- D. 78.5 V
Explanation
Maximum emf in a rotating coil is εmax = NBAω, where N = 50, B = 0.5 T, A = 0.02 m2, ω = 2πf = 2π × 10 = 20π rad/s. Thus, εmax= 50 × 0.5 × 0.02 × 20π ≈ 31.4 V.
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