12. A constant current is sent through a helical coil. The coil:(A) tends to rotate about its axis(B) tends to get longer(C) tends to get shorter(D) produces zero magnetic field at its center(E) none of the above

14. The figure shows three resistors in series surrounding an infinitely long solenoid with a changing magnetic field; the resulting induced electric field drives a current counterclockwise, as shown. Which statement is true? (A) Both meters read 0.(B) Both meters read 2IR.(C) Both meters read IR.(D) Left-hand meter reads IR.(E) Right-hand meter reads IR.

12. A constant current is sent through a helical coil. The coil:

(A) tends to rotate about its axis

(B) tends to get longer

(C) tends to get shorter

(D) produces zero magnetic field at its center

(E) none of the above

相關試題

相關試卷