Practice Midterm 03-problems - barron(jmb7952 Practice...

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barron (jmb7952) – Practice Midterm 03 – yao – (56125) 1 This print-out should have 18 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0points A 1 . 68 H inductor carries a steady current of 0 . 518 A. When the voltage source in the circuit is shorted out, the current disappears in 15 . 1 ms. What is the average induced emf in the inductor during this time? Answer in units of V. 002 10.0points How does the current in the secondary of the transformer compare with the current in the primary when the secondary voltage is twice the primary voltage? I 2 V rms 1. the same as the current in the primary L R t R b C V rms Find the rms current I delivered by the power supply when the frequency is very small. 1. I V rms ( R t + R b ) R t R b 2. I 2 V rms
2. twice the current in the primary
3. Sometimes these two currents are not
related to each other. 4. half the current in the primary
003 10.0points What is the rms current?
What current is required in the windings of a long solenoid that has 2040 turns uni- formly distributed over a length of 0 . 168 m in order to produce a magnetic field of magnitude 0 . 000316 T at the center of the solenoid? The permeability of free space is 4 π × 10 7 T · m / A . Answer in units of mA. 004 10.0points Consider the circuit
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