The energy stored in a solenoid inductor is 28.4 mJ. The solenoid has 425 turns, is .876 meters long and has a diameter of 37.2 cm. How much current is flowing through the solenoid inductor? A. 1.00 A B. 2.02 A C. 4.68 A D. .225 A E. 1.42 A

A 60V motor has an ammeter hooked up to it. At motor start up, the reading is BA. A moment later, the reading drops to 2A. What is the back emf of this etectric motor? Select one: a. 30V b. 50V C. 45V d. 180V

A generator produces 18.0 V when turning at 910 rev/min. What emf does it produce when turning at 540 rev/min? V

31. A single loop of wire of radius 0.23 m is placed in a 0.75 T magnetic field as shown. The magnetic field is changed to a strength of 0.50 T in the opposite direction in 0.61 s. X D. X X X X X +0.23 m Before X X X B X X What is the average emf induced in the coil? A. 0.068 V B. 0.094 V C. 0.34 V 0.47 V 0.23 m After Ein 10 ● B

R $₁ S₂ 2 L (...) E A 3 H inductor, a 9.75 9 resistor, and a 1.4 V battery are connected as shown above. The circuit also contain two switches, S₁ and S₂. Initially both switches are open. At t = 0 s S₁ is closed while S₂ is left open. a. What is the time constant of the resulting circuit? Submit Answer Tries 0/10 b1. What is the current through the circuit at t = 0 s? b2. What is the current through the circuit after a long time has passed? Submit Answer Tries 0/10 c1. What is the magnitude of the induced emf at t = 0 s? c2. What is the magnitude of the induced emf after a long time has passed? Submit Answer Tries 0/10 d. After the current in the RL circuit has reached its final value (as in b2. above) the positions of the switches are reversed, with S₁ open and S₂. How long does it take for the current to reach a tenth of its initial value?

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.

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

1 4 1: 5 * C 3.3 kN Find the Current through R5 2.5 A R, R. ww R3 1 A R6 R2 R5 Write the Kirchoff's loop equations for this circuit 5 R1 R2 500 10V 1000 8V 40V R3 2000 2.

A. Find the current in the loop at t = 1.5 s. B. Find the current in the loop at t = 2.5 s.

A conducting wire loop of radius 12 cm, that contains a 4.0-2 resistor, is in the presence of a uniform magnetic field of strength 3.0 T that is perpendicular to the plane of the loop. If the magnetic field is turned off in a time of 0.50 s, what is the current induced in the loop? a. 52 mA b. 68 mA O c. 95 mA d. 117 mA O e. 168 mA