1) A bar magnet with its north pole pointing toward a coil of wire with a cross-
ID: 2026512 • Letter: 1
Question
1) A bar magnet with its north pole pointing toward a coil of wire with a cross-sectional area of .020 m^2 and secen turns is thrust into the coil. If the rate of change in the strength of the magnetic field caused by the motion of the bar magnet is .040 T/s, what is the direction of the induced emf in the coil of wire (when looking at the end of the coil where the N pole is coming toward you)?A. Clockwise
B. Counterclockwise
C. No emf is induced.
2)The energy stored in a coil of self-inductance, L, and traversed by current I, is E1. A second coil is made with the same length of wire, but its radius is twice the radius of the first coil and it is twice as long as the first coil. If the second coil also has twice the current of the first coil, how does the energy stored in the first coil, E1, compare to the energy stored in the second coil, E2?
A. E1=E2/4 B. E1=E2/8 C. E1=E2/2 D. E1=4E2 E. E1=E2