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 11, Problem 93CP
A factory has the following four major loads:
- A motor rated at 5 hp, 0.8 pf lagging (1hp = 0.7457 kW).
- A heater rated at 1.2 kW, 1.0 pf.
- Ten 120-W lightbulbs.
- A synchronous motor rated at 1.6 kVAR, 0.6 pf leading.
- (a) Calculate the total real and reactive power.
- (b) Find the overall power factor.
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1. An electro-magnet draws 3 kW of active power and 4 kvar of reactive power.
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2. A capacitor drawing 4 kvar is placed in parallel with the electro-magnet of Question
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Chapter 11 Solutions
Fundamentals of Electric Circuits
Ch. 11.2 - Calculate the instantaneous power and average...Ch. 11.2 - A current A flows through an impedance Find the...Ch. 11.2 - In the circuit of Fig. 11.4, calculate the average...Ch. 11.2 - Calculate the average power absorbed by each of...Ch. 11.3 - For the circuit shown in Fig. 11.10, find the load...Ch. 11.3 - In Fig. 11.12, the resistor RL is adjusted until...Ch. 11.4 - Find the rms value of the current waveform of Fig....Ch. 11.4 - Find the rms value of the full-wave rectified sine...Ch. 11.5 - Prob. 9PPCh. 11.5 - Prob. 10PP
Ch. 11.6 - For a load, Determine: (a) the complex and...Ch. 11.6 - A sinusoidal source supplies 100 kVAR reactive...Ch. 11.7 - In the circuit in Fig. 11.25, the 60- resistor...Ch. 11.7 - Two loads connected in parallel are respectively 3...Ch. 11.8 - Find the value of parallel capacitance needed to...Ch. 11.9 - For the circuit in Fig. 11.33, find the wattmeter...Ch. 11.9 - The monthly reading of a paper mills meter is as...Ch. 11.9 - An 500-kW induction furnace at 0.88 power factor...Ch. 11 - The average power absorbed by an inductor is zero,...Ch. 11 - The Thevenin impedance of a network seen from the...Ch. 11 - The amplitude of the voltage available in the...Ch. 11 - If the load impedance is 20 j20, the power factor...Ch. 11 - A quantity that contains all the power information...Ch. 11 - Reactive power is measured in: (a) watts (b) VA...Ch. 11 - In the power triangle shown in Fig. 11.34(a), the...Ch. 11 - For the power triangle in Fig. 11.34(b), the...Ch. 11 - A source is connected to three loads Z1, Z2, and...Ch. 11 - The instrument for measuring average power is the:...Ch. 11 - If v(t) = 160 cos 50t V and i(t) = 33 sin (50t ...Ch. 11 - Given the circuit in Fig. 11.35, find the average...Ch. 11 - A load consists of a 60- resistor in parallel with...Ch. 11 - Using Fig. 11.36, design a problem to help other...Ch. 11 - ssuming that vs = 8 cos(2t 40) V in the circuit...Ch. 11 - For the circuit in Fig. 11.38, is = 6 cos 103t A....Ch. 11 - Given the circuit of Fig. 11.39, find the average...Ch. 11 - In the circuit of Fig. 11.40, determine the...Ch. 11 - For the op amp circuit in Fig. 11.41, Find the...Ch. 11 - In the op amp circuit in Fig. 11.42, find the...Ch. 11 - For the network in Fig. 11.43, assume that the...Ch. 11 - For the circuit shown in Fig. 11.44, determine the...Ch. 11 - The Thevenin impedance of a source is ZTh = 120 +...Ch. 11 - Using Fig. 11.45, design a problem to help other...Ch. 11 - In the circuit of Fig. 11.46, find the value of ZL...Ch. 11 - For the circuit in Fig. 11.47, find the value of...Ch. 11 - Calculate the value of ZL in the circuit of Fig....Ch. 11 - Find the value of ZL in the circuit of Fig. 11.49...Ch. 11 - The variable resistor R in the circuit of Fig....Ch. 11 - The load resistance RL in Fig. 11.51 is adjusted...Ch. 11 - Assuming that the load impedance is to be purely...Ch. 11 - Find the rms value of the offset sine wave shown...Ch. 11 - Using Fig. 11.54, design a problem to help other...Ch. 11 - Determine the rms value of the waveform in Fig....Ch. 11 - Find the rms value of the signal shown in Fig....Ch. 11 - Find the effective value of the voltage waveform...Ch. 11 - Calculate the rms value of the current waveform of...Ch. 11 - Find the rms value of the voltage waveform of Fig,...Ch. 11 - Calculate the effective value of the current...Ch. 11 - Compute the rms value of the waveform depicted in...Ch. 11 - Find the rms value of the signal shown in Fig....Ch. 11 - Obtain the rms value of the current waveform shown...Ch. 11 - Determine the rms value for the waveform in Fig....Ch. 11 - Find the effective value f(t) defined in Fig....Ch. 11 - One cycle of a periodic voltage waveform is...Ch. 11 - Calculate the rms value for each of the following...Ch. 11 - Design a problem to help other students better...Ch. 11 - For the power system in Fig. 11.67, find: (a) the...Ch. 11 - An ac motor with impedance ZL = 2 + j 1.2 is...Ch. 11 - Design a problem to help other students better...Ch. 11 - Obtain the power factor for each of the circuits...Ch. 11 - A 110-V rms, 60-Hz source is applied to a load...Ch. 11 - Design a problem to help other students understand...Ch. 11 - Find the complex power delivered by vs to the...Ch. 11 - The voltage across a load and the current through...Ch. 11 - For the following voltage and current phasors,...Ch. 11 - For each of the following cases, find the complex...Ch. 11 - Determine the complex power for the following...Ch. 11 - Find the complex power for the following cases:...Ch. 11 - Obtain the overall impedance for the following...Ch. 11 - For the entire circuit in Fig. 11.70, calculate:...Ch. 11 - In the circuit of Fig. 11.71, device A receives 2...Ch. 11 - In the circuit of the Fig. 11.72, load A receives...Ch. 11 - For the network in Fig. 11.73, find the complex...Ch. 11 - Using Fig. 11.74, design a problem to help other...Ch. 11 - Obtain the complex power delivered by the source...Ch. 11 - For the circuit in Fig. 11.76, find the average,...Ch. 11 - Obtain the complex power delivered to the 10-k...Ch. 11 - Calculate the reactive power in the inductor and...Ch. 11 - For the circuit in Fig. 11.79, find Vo and the...Ch. 11 - Given the circuit in Fig. 11.80, find Io and the...Ch. 11 - For the circuit in Fig. 11.81, find Vs.Ch. 11 - Find Io in the circuit of Fig. 11.82. Figure 11.82Ch. 11 - Determine Is in the circuit of Fig. 11.83, if the...Ch. 11 - In the op amp circuit of Fig. 11.84, vs = 4 cos...Ch. 11 - Obtain the average power absorbed by the 10-...Ch. 11 - For the op amp circuit in Fig. 11.86, calculate:...Ch. 11 - Compute the complex power supplied by the current...Ch. 11 - Refer to the circuit shown in Fig. 11.88. (a) What...Ch. 11 - Design a problem to help other students better...Ch. 11 - Three loads are connected in parallel to a rms...Ch. 11 - Two loads connected in parallel draw a total of...Ch. 11 - A 240-V rms 60-Hz supply serves a load that is 10...Ch. 11 - A 120-V rms 60-Hz source supplies two loads...Ch. 11 - Consider the power system shown in Fig. 11.90....Ch. 11 - Obtain the wattmeter reading of the circuit in...Ch. 11 - What is the reading of the wattmeter in the...Ch. 11 - Find the wattmeter reading of the circuit shown in...Ch. 11 - Determine the wattmeter reading of the circuit in...Ch. 11 - The circuit of Fig. 11.95 portrays a wattmeter...Ch. 11 - Design a problem to help other students better...Ch. 11 - A 240-V rms 60-Hz source supplies a parallel...Ch. 11 - Oscilloscope measurements indicate that the peak...Ch. 11 - A consumer has an annual consumption of 1200 MWh...Ch. 11 - A regular household system of a single-phase...Ch. 11 - A transmitter delivers maximum power to an antenna...Ch. 11 - In a TV transmitter, a series circuit has an...Ch. 11 - A certain electronic circuit is connected to a...Ch. 11 - An industrial heater has a nameplate that reads:...Ch. 11 - A 2000-kW turbine-generator of 0.85 power factor...Ch. 11 - The nameplate of an electric motor has the...Ch. 11 - As shown in Fig. 11.97, a 550-V feeder line...Ch. 11 - A factory has the following four major loads: A...Ch. 11 - A 1-MVA substation operates at full load at 0.7...Ch. 11 - Prob. 95CPCh. 11 - A power amplifier has an output impedance of 40 +...Ch. 11 - A power transmission system is modeled as shown in...
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