30. Induction and Inductance

A 30mH inductor carries a current of 500mA. If the circuit is opened and the current stops over a period of 3.0μs, what potential develops across the inductor?

A toroidal solenoid has mean radius 12.0 cm and crosssectional area 0.600 cm². How many turns does the solenoid have if its inductance is 0.100 mH?

The inductor shown in Fig. E30.11 has inductance 0.260 H and carries a current in the direction shown. The current is changing at a constant rate. The potential between points a and b is V_ab = 1.04 V, with point a at higher potential. Is the current increasing or decreasing?

When the current in a toroidal solenoid is changing at a rate of 0.0260 A/s, the magnitude of the induced emf is 12.6 mV. When the current equals 1.40 A, the average flux through each turn of the solenoid is 0.00285 Wb. How many turns does the solenoid have?

What is the potential difference across a 10 mH inductor if the current through the inductor drops from 150 mA to 50 mA in 10 μs? What is the direction of this potential difference? That is, does the potential increase or decrease along the direction of the current?