a) A transformer draws 28 W of power from a 220 V power line, stepping the voltage down to 8 V. What will be the equivalent resistance of the input circuit?
b) The magnetic field in the region between the poles of an electromagnet is uniform at any time, but is increasing at the rate of 0.060 T/s. The area of the conduction loop in the field is 120 cm^2, and the total circuit resistance, including the meter, is 6.0 ohms. What is the magnitude of the induced emf?
c) A coil with 500 turns enclosing an area of 10 cm^2 is rotated from a position where its planes is perpendicular to earth's magnetic field to one where its plane is parallel to the field. The rotation takes 0.050 s. What is the average emf induced in the coil?