Fall 2012 Midterm 3 Solutions

# An ac generator operating at a frequency of f 60

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Unformatted text preview: . An AC generator operating at a frequency of f = 60 cycles/second has an RMS emf of 80 V. It is connected to the leads of a 2.0 x 10-4 F capacitor with negligible resistance. What is the RMS current supplied by the generator (in A)? A) 27 B) 13 C) 19 D) 6.0 E) 42 3. The inductor is a solenoid with an internal resistance of R = 0.15 What is the current flowing through the battery 8 seconds after closing the switch? 6V A) B) C) D) E) L 30 A 3A 40 A 18 A 12 A Version 1 Page 2 2H 4. A circular coil of wire has 25 turns and has a radius of 0.075 m. The coil is located in a variable magnetic field whose behavior is shown on the graph. At all times, the magnetic field is directed at an angle of 75° relative to the normal to the plane of a loop. What is the average emf induced in the coil in the time interval from t = 5.00 s to 7.50 s? A) B) C) D) E) 180 mV 140 mV 18 mV 92 mV 49 mV 5. A cylindrical region of radius R contains a uniform conduction current density, parallel to t The time dependence of J is irrelevant because no time derivatives appear in the conduction current part of amperes law. its axis, with magnitude that is exponentially decaying with time, J (t ) J 0e . The magnitude of the magnetic field at radius r at a particular moment in time inside the cylindrical region (r<R) is proportional to: A) r0 (constant) B) r C ) r2 D) 1/r E) 1/r2 6. A toroidal solenoid with 400 turns of wire and a mean radius of 6.0 cm carrie...
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## This document was uploaded on 03/11/2014 for the course PHYSICS 240 at University of Michigan.

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