Answer: 0.56 A.
- A 0.25 A
- B 2.00 A
- C 1.00 A
- D 0.56 A
Correct answer: D. 0.56 A
Explanation: Secondary voltage = 220 V, so secondary current = 220/44 = 5 A. Output power = 1100 W. Input power = 1100/0.9 = 1222 W. Primary current = 1222/2200 = 0.56 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.