Exam4Solutions-Spring09

Exam4Solutions-Spring09 - c What is the power flowing into...

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Question 1. a) Is the machine acting as a motor or a generator? Explain. If the speed of rotation ω of the shaft is 500 rad/s, then the induced voltage will be Since the external batter is 48 volts, the machine is operating as a generator charging the battery. b) What is the current flowing into or out of the loop? The current flowing out of the loop is approximately* *Note that this current is flowing while the loop is under the pole faces. When the loop goes beyond the pole faces the induced voltage will momentarily drop to zero and the current flow will momentarily reverse. Therefore the average current flow will be somewhat less than 5.0 amps.

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Unformatted text preview: c) What is the power flowing into or out of the machine? What is the torque? Neglect losses. d) If the speed were changed to 550 rad/s what would happen to the current? If the speed were increases to 550 rad/s the induced voltage would increase to 55 volts and the current would increase to 17.5 amps. e) If the speed were changed to 450 rad/s what would happen to the current? If the speed were decreases to 450 rad/s the induced voltage would decrease to 45 volts. Since this is less than the battery voltage current would flow into the loop and the machine would act as a motor. The resulting current would be 7.5 amps. Question 2....
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This note was uploaded on 07/28/2011 for the course EEL 3211 taught by Professor Staff during the Summer '08 term at University of Florida.

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Exam4Solutions-Spring09 - c What is the power flowing into...

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