Question

A scientist creates a “magnet detector” by attaching a current meter to a single loop of wire (Ndet=1). The wire loop has a radius of 10.0cm and a resistance of 0.0200.    

1. To test the device, the scientist moves the North pole of a bar magnet toward the wire loop. This causes the magnetic field inside the loop to increase from 0.00T to 4.5010-3T in a time of 0.250sec. Calculate the induced current measured in the wire loop.   

2. In another test, the scientist puts the detector loop inside of a solenoid. The solenoid has 500 loops and a length of 12 cm. Current is supplied to the solenoid by a power supply with an on/off switch. The current is initially off, and once turned on carries 230 mA. It takes 0.250 seconds to ramp up the current to a steady value. When the scientist hits the switch, what is the magnitude of the current induced in the detector loop? (Hint: This is a 3-step problem.)

Answer 1