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Serway_CP_poll_ch20

# Serway_CP_poll_ch20 - An RL circuit in which L = 0.4 H and...

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An RL circuit in which L = 0.4 H and R = 5 W is connected to a battery with E = 22 V at time t = 0. What energy is stored in the inductor when the current in the circuit is 0.5 A? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 500 mJ 2. 1.0 J 3. 2.0 J 4. 5.0 J

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You can calculate the induced current in a ring by setting the emf from a changing flux E = -DØ/Dt equal to the voltage change -LDI/Dt in an inductor. If the magnetic field through a ring of area 1 cm 2 collapses from 0.02 T to zero and the inductance of the ring is 10 -7 H, what is the induced current in the ring? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 5 A 2. 10 A 3. 15 A 4. 20 A
Superconductors have been discussed as a means for electrical energy storage. Because they are resistanceless, a current once started in a loop would continue without loss. If a current of 10 4 A were started in a huge toroidal coil of radius 1 km and inductance 50 H, how much electrical energy (in kW hours) could be stored? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 300 kWH 2. 482 kWH 3. 694 kWH 4. 842 kWH

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A small airplane with a wing span of 12 m flies horizontally and due north at a speed of 60 m/s in a region where the magnetic field of the earth is 60 µT directed 60° below the horizontal. What is the magnitude of the induced emf between the ends of the wing? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 50 mV 2. 31 mV 3. 37 mV 4. 44 mV
What is the minimum frequency with which a 200-turn, flat coil of cross-sectional area of 300 cm 2 can be rotated in a uniform 30-mT magnetic field if the maximum value of the induced emf is to equal 8.0 V? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 7.5 Hz 2. 7.1 Hz 3. 8.0 Hz 4. 8.4 Hz

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A series circuit contains a 12-V battery, a 2000 W resistor, and a 3 mH inductor. If the switch to the battery is closed at t = 0, find the time required for the current in the circuit to reach 63% of its final value. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. 1.5 ms 2. 3.0 ms 3. 4.0 ms 4. 5.0 ms
A circular loop (area = 0.20 m 2 ) turns in a uniform magnetic field with B = 0.13 T. At an instant when the angle between the magnetic field and the normal to the plane of the loop is π rads and is decreasing at the rate of 0.50 rad/s, what is the magnitude of the emf induced in the loop? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 1. zero 2. 13 mV 3. 26 mV 4. 20 mV

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A flat coil of wire consisting of 20 turns, each with an area of 50 cm 2 , is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 2.0 T to 6.0 T in 2.0 s. If the coil has a total resistance of 0.40 W, what is the magnitude of the induced current?
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