Two parallel conductors are carrying currents in the same direction. The currents are non-zero and not necessarily equal. The magnitude of the magnetic field midway between them is 40 mT. If one of the currents then has its direction reversed, what is the resulting magnitude of the magnetic field midway between them?
a. It could be any value.
c. a value less than 40 mT
b. 40 mT
d. a value greater than 40 mT
D
You might also like to view...
By comparing the two images, what can you conclude about Io's volcanoes?
A) Every black spot in the visible image has a bright spot in the infrared image, so all of Io's volcanoes were active when the photos were taken. B) There are more black spots in the visible image than bright spots in the infrared image, so many of Io's volcanoes were inactive when the photos were taken. C) There are more bright spots in the infrared image than black spots in the visible image, so new eruptions must have started after the visible photo was taken.
The discovery of extrasolar planets indicates that planets around other stars are
A) all Earth-like B) nonexistent C) common D) relatively rare
A square loop (length along one side = 20 cm) rotates in a constant magnetic field which has a magnitude of 2.0 T. At an instant when the angle between the field and the normal to the plane of the loop is equal to 20° and increasing at the rate of 10°/s, what is the magnitude of the induced emf in the loop?
A. 13 mV B. 0.27 V C. 4.8 mV D. 14 mV E. 2.2 mV
For large mass number nuclei which are stable, the ratio of protons to neutrons is
a. equal to 1 b. greater than 1 c. less than 1 d. unrelated to the stability of nuclei e. almost 2 to 1