Answer: 12.5 A.
- A 10.0 A
- B 11.0 A
- C 14.0 A
- D 12.5 A
Correct answer: D. 12.5 A
Explanation: Output power = 1100 × 2 = 2200 W. Input power = 2200/0.8 = 2750 W. Therefore primary current = 2750/220 = 12.5 A.
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.