A solenoid with an inductance of 14 mH is charged up from an initial current of 3.0 A to a current of 7.0 A in a time of 0.12 s. What is the magnitude of the self-induced EMF in the solenoid?   a. 0.47 volts   b. 0.22 volts   c. 0.73 volts   d. 0.34 volts   e. 0.13 volts

4 The circuit given to the right has been on for a long time. a. Determine the energy stored in the capacitor. 12 mH 16 k2 18 k2 15 V 1.5μF. 9k 2 b. Determine the energy stored in the inductor. c. Determine how high you could lift a 1.0mg object on Earth if you could convert all of the capacitor's and inductor's stored energy into gravitational potential energy.

19. A buzzer with an inductance of 15 H and a resistance of 800 Ω         operates with 15 mA. What time will elapse after a 20 V         battery is switched across the buzzer before the current         reaches the operating values?         A. 17.18 μs          B. 15.17 μs         C. 18.72 ms         D. 17.18 ms

An inductor L = 0.025 H and a 40 Ω resistor are connected in series to a 5 volt battery and a switch. At t = 0, the switch is closed to complete the circuit. a) What is the potential difference across the resistor a long time after the switch is closed? b) From the time the switch is closed, how long does it take for the current to reach 63% of the maximum value? c) For a single loop circuit with a 2 Ω resistor, a single battery of 3 V, and a characteristic size (size of the loop) of 15.0 cm, the estimated inductance is 2 ✕ 10−7 H. What is the time constant of this RL circuit?

2

In the circuit shown, the switch S is closed at time t=0. a) Find the current in the 100 2 resistor immediately after the switch is closed. b) Find the current in the 10 fesistor immediately after the switch is closed. c) Find the current I in the inductor at the switch has been closed. T is a very long time after the switch has been closed

4. Inductance of a long solenoid: A long thin solenoid has N turns, a length W, area A and a current I. a. What is the magnetic flux through one turn of the solenoid? 6 per turn = BA= b. Determine the inductance L of the solenoid. LI= NO. per turn c. A very long solenoid has 500 turns, a radius of 2 cm and a length of 40 cm and a current of 3A. What is the inductance of the solenoid? d. The coil in an inductor is usually wrapped around an iron core which amplifies the magnetic field. Assume the iron core makes the magnetic field 700 times larger than without the core. What is the inductance of the solenoid in (c) with the iron core? 600 # 212 RCE

When the current in a solenoid uniformly increases from 3.0 A to 8.0 A in a time 0.25 s, the induced EMF is 0.50 volts. What is the inductance of the solenoid?   a. 25 mH   b. 40 mH   c. 30 mH   d. 35 mH   e. 20 mH

V06

You need an inductor that will store 20 J of energy when a 3.0-A current flows through it. What should be its self-inductance? O 3.7 H O 90 H O 60 H O 4.4 H O 76 H