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 94CP
A 1-MVA substation operates at full load at 0.7 power factor. It is desired to improve the power factor to 0.95 by installing capacitors. Assume that new substation and distribution facilities cost $120 per kVA installed, and capacitors cost $30 per kVA installed.
- (a) Calculate the cost of capacitors needed.
- (b) Find the savings in substation capacity released.
- (c) Are capacitors economical for releasing the amount of substation capacity?
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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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