In figure the rolling axle, 1.50 m long, is pushed along horizontal rails at a constant speed v = 3.00 m/s. A resistor R = 0.400 ? is connected to the rails at points a and b, directly opposite each other. (The wheels make good electrical contact with the rails, so the axle, rails, and R form a closed-loop circuit. The only significant resistance in the circuit is R.) A uniform magnetic field B = 0.800 T is directed vertically downwards.

(a) Find the induced current I in the resistor.

(b) What horizontal force F is required to keep the axle rolling at constant speed?

(c) Which end of the resistor, a or b, is at the higher electric potential?

(d) After the axle rolls past the resistor, does the current in R reversedirection?

Transcribed Image Text:

R b B