Fundamentals of Electric Circuits
6th Edition
ISBN: 9780078028229
Author: Charles K Alexander, Matthew Sadiku
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 13, Problem 67P
An autotransformer with a 40 percent tap is supplied by an 880-V, 60-Hz source and is used for step-down operation. A 5-kVA load operating at unity power factor is connected to the secondary terminals. Find:
- (a) the secondary voltage,
- (b) the secondary current,
- (c) the primary current.
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1) A single-phase 100-kVA, 2,400/240 V, 60-Hz distribution transformer is used as a step-down transformer. The load, which is connected to the 240 V secondary winding, absorbs 80 kVA at 0.8 power factor lagging and is at 230 V. Assuming an ideal transformer, calculate the following:
(a) primary voltage;(b) load impedance;(c) load impedance referred to the primary;(d) the active and reactive power supplied to the primary winding.
A single-phase 100-kVA, 2,400/240 V, 60-Hz distribution transformer is used as a step-down transformer. The load, which is connected to the 240 V secondary winding, absorbs 80 kVA at 0.8 power factor lagging and is at 230 V. Assuming an ideal transformer, calculate the following:(a) primary voltage;(b) load impedance;(c) load impedance referred to the primary;(d) the active and reactive power supplied to the primary winding.
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Chapter 13 Solutions
Fundamentals of Electric Circuits
Ch. 13.2 - Determine the voltage Vo in the circuit of Fig....Ch. 13.2 - Determine the phasor currents I1 and I2 in the...Ch. 13.3 - Prob. 3PPCh. 13.4 - Find the input impedance of the circuit in Fig....Ch. 13.4 - For the linear transformer in Fig. 13.26(a), find...Ch. 13.4 - Solve the problem in Example 13.1 (see Fig. 13.9)...Ch. 13.5 - The primary current to an ideal transformer rated...Ch. 13.5 - In the ideal transformer circuit of Fig. 13.38,...Ch. 13.5 - Find Vo in the circuit of Fig. 13.40. Figure 13.40...Ch. 13.6 - Refer to Fig. 13.43. If the two-winding...
Ch. 13.6 - In the autotransformer circuit of Fig. 13.45, find...Ch. 13.7 - Prob. 12PPCh. 13.8 - Prob. 13PPCh. 13.9 - Refer to Fig. 13.61. Calculate the turns ratio...Ch. 13.9 - Calculate the turns ratio of an ideal transformer...Ch. 13.9 - In Example 13.17, if the eight 100-W bulbs are...Ch. 13 - Refer to the two magnetically coupled coils of...Ch. 13 - Prob. 2RQCh. 13 - Prob. 3RQCh. 13 - Prob. 4RQCh. 13 - The ideal transformer in Fig. 13.70(a) has N2/N1 =...Ch. 13 - Prob. 6RQCh. 13 - A three-winding transformer is connected as...Ch. 13 - Prob. 8RQCh. 13 - Prob. 9RQCh. 13 - Prob. 10RQCh. 13 - For the three coupled coils in Fig. 13.72,...Ch. 13 - Using Fig. 13.73, design a problem to help other...Ch. 13 - Two coils connected in series-aiding fashion have...Ch. 13 - (a) For the coupled coils in Fig. 13.74(a), show...Ch. 13 - Two coils are mutually coupled, with L1 = 50 mH,...Ch. 13 - Given the circuit shown in Fig. 13.75, determine...Ch. 13 - For the circuit in Fig. 13.76, find Vo. Figure...Ch. 13 - Find v(t) for the circuit in Fig. 13.77.Ch. 13 - Prob. 9PCh. 13 - Find vo in the circuit of Fig. 13.79. Figure 13.79...Ch. 13 - Use mesh analysis to find ix in Fig. 13.80, where...Ch. 13 - Determine the equivalent Leq in the circuit of...Ch. 13 - For the circuit in Fig. 13.82, determine the...Ch. 13 - Obtain the Thevenin equivalent circuit for the...Ch. 13 - Find the Norton equivalent for the circuit in Fig....Ch. 13 - Obtain the Norton equivalent at terminals a-b of...Ch. 13 - In the circuit of Fig. 13.86, ZL is a 15-mH...Ch. 13 - Find the Thevenin equivalent to the left of the...Ch. 13 - Determine an equivalent T-section that can be used...Ch. 13 - Determine currents I1, I2, and I3 in the circuit...Ch. 13 - Prob. 21PCh. 13 - Find current Io in the circuit of Fig. 13.91.Ch. 13 - Let is = 5 cos (100t) A. Calculate the voltage...Ch. 13 - In the circuit of Fig. 13.93, (a) find the...Ch. 13 - Prob. 25PCh. 13 - Find Io in the circuit of Fig. 13.95. Switch the...Ch. 13 - Find the average power delivered to the 50-...Ch. 13 - In the circuit of Fig. 13.97, find the value of X...Ch. 13 - Prob. 29PCh. 13 - (a) Find the input impedance of the circuit in...Ch. 13 - Using Fig. 13.100, design a problem to help other...Ch. 13 - Two linear transformers are cascaded as shown in...Ch. 13 - Determine the input impedance of the air-core...Ch. 13 - Using Fig. 13.103, design a problem to help other...Ch. 13 - Find currents I1, I2, and I3 in the circuit of...Ch. 13 - As done in Fig. 13.33, obtain the relationships...Ch. 13 - A 2402,400-V rms step-up ideal transformer...Ch. 13 - Design a problem to help other students better...Ch. 13 - A 1,200240-V rms transformer has impedance on the...Ch. 13 - The primary of an ideal transformer with a turns...Ch. 13 - Given I2 = 2 A, determine the value of Is in Fig....Ch. 13 - For the circuit in Fig. 13.107, determine the...Ch. 13 - Obtain V1 and V2 in the ideal transformer circuit...Ch. 13 - In the ideal transformer circuit of Fig. 13.109,...Ch. 13 - For the circuit in Fig. 13.110, find the value of...Ch. 13 - (a) Find I1 and I2 in the circuit of Fig. 13.111...Ch. 13 - Prob. 47PCh. 13 - Using Fig. 13.113, design a problem to help other...Ch. 13 - Find current ix in the ideal transformer circuit...Ch. 13 - Prob. 50PCh. 13 - Use the concept of reflected impedance to find the...Ch. 13 - For the circuit in Fig. 13.117, determine the...Ch. 13 - Refer to the network in Fig. 13.118. (a) Find n...Ch. 13 - A transformer is used to match an amplifier with...Ch. 13 - For the circuit in Fig. 13.120, calculate the...Ch. 13 - Find the power absorbed by the 100- resistor in...Ch. 13 - For the ideal transformer circuit of Fig. 13.122...Ch. 13 - Determine the average power absorbed by each...Ch. 13 - In the circuit of Fig. 13.124, let vs = 165...Ch. 13 - Refer to the circuit in Fig. 13.125 on the...Ch. 13 - For the circuit in Fig. 13.126, find Il, I2, and...Ch. 13 - For the network in Fig. 13.127, find: (a) the...Ch. 13 - Find the mesh currents in th circuit of Fig....Ch. 13 - For the circuit in Fig. 13.129. find the turns...Ch. 13 - Calculate the average power dissipated by the 20-...Ch. 13 - Design a problem to help other students better...Ch. 13 - An autotransformer with a 40 percent tap is...Ch. 13 - In the ideal autotransformer of Fig. 13.131,...Ch. 13 - In the circuit of Fig. 13.131, N1 = 190 turns and...Ch. 13 - In the ideal transformer circuit shown in Fig....Ch. 13 - When individuals travel, their electrical...Ch. 13 - In order to meet an emergency, three single-phase...Ch. 13 - Figure 13.135 on the next page shows a three-phase...Ch. 13 - Consider the three-phase transformer shown in Fig....Ch. 13 - A balanced three-phase transformer bank with the...Ch. 13 - Using Fig. 13.138, design a problem to help other...Ch. 13 - The three-phase system of a town distributes power...Ch. 13 - Use PSpice or MultiSim to determine the mesh...Ch. 13 - Use PSpice or MultiSim to find I1, I2, and I3 in...Ch. 13 - Prob. 80PCh. 13 - Use PSpice or MultiSim to find I1, I2, and I3 in...Ch. 13 - A stereo amplifier circuit with ail output...Ch. 13 - A transformer having 2,400 turns on the primary...Ch. 13 - A radio receiver has an input resistance of 300 ....Ch. 13 - A step-down power transformer with a turns ratio...Ch. 13 - A 240120-V rms power transformer is rated at 10...Ch. 13 - A 4-kVA, 2,400240-V rms transformer has 250 turns...Ch. 13 - A 25,000240-V rms distribution transformer has a...Ch. 13 - A 4,800-V rms transmission line feeds a...Ch. 13 - A four-winding transformer (Fig. 13.146) is often...Ch. 13 - A 440/110-V ideal transformer can be connected to...Ch. 13 - Ten bulbs in parallel are supplied by a 7,200120-V...
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