Serway_CP_poll_ch20

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

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Unformatted text preview: 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1. 500 mJ 2. 1.0 J 3. 2.0 J 4. 5.0 J 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1. 300 kWH 2. 482 kWH 3. 694 kWH 4. 842 kWH 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1. 7.5 Hz 2. 7.1 Hz 3. 8.0 Hz 4. 8.4 Hz 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 25% 25% 25% 25% 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 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?emf induced in the loop?...
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Serway_CP_poll_ch20 - An RL circuit in which L = 0.4 H and...

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