Answer: 0.00866 Wb.
- A 0.00866 Wb
- B 0.01732 Wb
- C 0.02000 Wb
- D 0.00500 Wb
Correct answer: A. 0.00866 Wb
Explanation: Φ = B·A·cosθ = 0.5 × 0.02 × cos30° = 0.5 × 0.02 × 0.866 ≈ 0.00866 Wb.
As a magnet approaches a coil, flux rises steadily and a constant non-zero EMF is induced (Faraday's law). Once the magnet stops moving, flux stays constant and the induced EMF drops to zero - EMF only exists while flux is actively changing.
Concept context
Faraday's and Lenz's laws, motional EMF, self/mutual inductance, eddy currents, and the AC generator - how a changing magnetic flux creates an electric current.