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 7.9, Problem 21PP
A relay has a resistance of 200 Ω and an inductance of 500 mH. The relay contacts close when the current through the coil reaches 175 μA. What time elapses between the application of 110 V to the coil and contact closure?
Answer: 957.5 μs.
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Chapter 7 Solutions
Fundamentals of Electric Circuits
Ch. 7.2 - Refer to the circuit in Fig. 7.7. Let vC (0) = 60...Ch. 7.2 - If the switch in Fig. 7.10 opens at t = 0, find...Ch. 7.3 - Find i and vx in the circuit of Fig. 7.15. Let...Ch. 7.3 - For the circuit in Fig. 7.18, find i(t) for t 0....Ch. 7.3 - Determine i, io, and vo for all t in the circuit...Ch. 7.4 - Express the current pulse in Fig. 7.33 in terms of...Ch. 7.4 - Refer to Fig. 7.39. Express i(t) in terms of...Ch. 7.4 - If h t = 0, t0 4, 0t2 3t8, 2t6 0, t6 express h(t)...Ch. 7.4 - Practice Problem 7.9 Evaluate the following...Ch. 7.5 - Find v(t) for t 0 in the circuit of Fig. 7.44....
Ch. 7.5 - The switch in Fig. 7.47 is closed at t = 0. Find...Ch. 7.6 - The switch in Fig. 7.52 has been closed for a long...Ch. 7.6 - Switch S1 in Fig. 7.54 is closed at t = 0, and...Ch. 7.7 - For the op amp circuit in Fig. 7.56, find vo for t...Ch. 7.7 - Find v(t) and vo(t) in the op amp circuit of Fig....Ch. 7.7 - Obtain the step response vo(t) for the circuit in...Ch. 7.8 - For the circuit in Fig. 7.66, use Pspice to find...Ch. 7.8 - The switch in Fig. 7.71 was open for a long time...Ch. 7.9 - The RC circuit in Fig. 7.74 is designed to operate...Ch. 7.9 - The flash unit of a camera has a 2-mF capacitor...Ch. 7.9 - A relay has a resistance of 200 and an inductance...Ch. 7.9 - Prob. 22PPCh. 7 - An RC circuit has R = 2 and C = 4 F. The time...Ch. 7 - The time constant for an RL circuit with R = 2 ...Ch. 7 - A capacitor in an RC circuit with R = 2 and C = 4...Ch. 7 - An RL circuit has R = 2 and L = 4 H. The time...Ch. 7 - In the circuit of Fig. 7.79, the capacitor voltage...Ch. 7 - Figure 7.79 For Review Questions 7.5 and 7.6....Ch. 7 - For the circuit in Fig. 7.80, the inductor current...Ch. 7 - Figure 7.80 For Review Questions 7.7 and 7.8....Ch. 7 - If vs changes from 2 V to 4 V at t = 0, we may...Ch. 7 - The pulse in Fig. 7.116(a) can be expressed in...Ch. 7 - In the circuit shown in Fig. 7.81...Ch. 7 - Find the time constant for the RC circuit in Fig....Ch. 7 - Determine the time constant for the circuit in...Ch. 7 - The switch in Fig. 7.84 has been in position A for...Ch. 7 - Using Fig. 7.85, design a problem to help other...Ch. 7 - The switch in Fig. 7.86 has been closed for a long...Ch. 7 - Assuming that the switch in Fig. 7.87 has been in...Ch. 7 - For the circuit in Fig. 7.88, if...Ch. 7 - The switch in Fig. 7.89 opens at t = 0. Find vo...Ch. 7 - For the circuit in Fig. 7.90, find vo(t) for t 0....Ch. 7 - For the circuit in Fig. 7.91, find io for t 0....Ch. 7 - Using Fig. 7.92, design a problem to help other...Ch. 7 - In the circuit of Fig. 7.93,...Ch. 7 - Calculate the time constant of the circuit in Fig....Ch. 7 - Find the time constant for each of the circuits in...Ch. 7 - Determine the time constant for each of the...Ch. 7 - Consider the circuit of Fig. 7.97. Find vo(t) if...Ch. 7 - For the circuit in Fig. 7.98, determine vo(t) when...Ch. 7 - In the circuit of Fig. 7.99, find i(t) for t 0 if...Ch. 7 - For the circuit in Fig. 7.100, v = 90e50t V and i...Ch. 7 - In the circuit of Fig. 7.101, find the value of R...Ch. 7 - Find i(t) and v(t) for t 0 in the circuit of Fig....Ch. 7 - Consider the circuit in Fig. 7.103. Given that...Ch. 7 - Express the following signals in terms of...Ch. 7 - Design a problem to help other students better...Ch. 7 - Express the signals in Fig. 7.104 in terms of...Ch. 7 - Express v(t) in Fig. 7.105 in terms of step...Ch. 7 - Sketch the waveform represented by i(t) = [r(t) ...Ch. 7 - Sketch the following functions: (a) x(t) = 10etu(t...Ch. 7 - Prob. 30PCh. 7 - Evaluate the following integrals: (a)e4t2(t2)dt...Ch. 7 - Prob. 32PCh. 7 - The voltage across a 10-mH inductor is 45(t 2)mV....Ch. 7 - Evaluate the following derivatives: (a) ddtut1ut+1...Ch. 7 - Find the solution to the following differential...Ch. 7 - Solve for v in the following differential...Ch. 7 - A circuit is described by 4dvdt+v=10 (a) What is...Ch. 7 - A circuit is described by didt+3i=2ut Find i(t)...Ch. 7 - Calculate the capacitor voltage for t 0 and t 0...Ch. 7 - Find the capacitor voltage for t 0 and t 0 for...Ch. 7 - Using Fig. 7.108, design a problem to help other...Ch. 7 - (a) If the switch in Fig. 7.109 has been open for...Ch. 7 - Consider the circuit in Fig. 7.110. Find i(t) for...Ch. 7 - The switch in Fig. 7.111 has been in position a...Ch. 7 - Find vo in the circuit of Fig. 7.112 when vs =...Ch. 7 - Prob. 46PCh. 7 - Determine v(t) for t 0 in the circuit of Fig....Ch. 7 - Find v(t) and i(t) in the circuit of Fig. 7.115....Ch. 7 - If the waveform in Fig. 7.116(a) is applied to the...Ch. 7 - In the circuit of Fig. 7.117, find ix for t 0....Ch. 7 - Rather than applying the shortcut technique used...Ch. 7 - Using Fig. 7.118, design a problem to help other...Ch. 7 - Determine the inductor current i(t) for both t 0...Ch. 7 - Obtain the inductor current for both t 0 and t 0...Ch. 7 - Find v(t) for t 0 and t 0 in the circuit of Fig....Ch. 7 - Prob. 56PCh. 7 - Prob. 57PCh. 7 - Rework Prob. 7.17 if i(0) = 10 A and v(t) = 20u(t)...Ch. 7 - Determine the step response vo(t) to is = 6u(t) A...Ch. 7 - Find v(t) for t 0 in the circuit of Fig. 7.125 if...Ch. 7 - In the circuit in Fig. 7.126, is changes from 5 A...Ch. 7 - For the circuit in Fig. 7.127, calculate i(t) if...Ch. 7 - Obtain v(t) and i(t) in the circuit of Fig. 7.128....Ch. 7 - Determine the value of iL(t) and the total energy...Ch. 7 - If the input pulse in Fig. 7.130(a) is applied to...Ch. 7 - Using Fig. 7.131, design a problem to help other...Ch. 7 - If v(0) = 10 V, find vo(t) for t 0 in the op amp...Ch. 7 - Prob. 68PCh. 7 - For the op amp circuit in Fig. 7.134, find vo(t)...Ch. 7 - Determine vo for t 0 when vs = 20 mV in the op...Ch. 7 - For the op amp circuit in Fig. 7.136, suppose vs =...Ch. 7 - Find io in the op amp circuit in Fig. 7.137....Ch. 7 - For the op amp circuit of Fig. 7.138, let R1 = 10...Ch. 7 - Determine vo(t) for t 0 in the circuit of Fig....Ch. 7 - In the circuit of Fig. 7.140, find vo and io,...Ch. 7 - Repeat Prob. 7.49 using PSpice or MultiSim. If the...Ch. 7 - The switch in Fig. 7.141 opens at t = 0. Use...Ch. 7 - The switch in Fig. 7.142 moves from position a to...Ch. 7 - In the circuit of Fig. 7.143, determine io(t)....Ch. 7 - In the circuit of Fig. 7.144, find the value of io...Ch. 7 - Repeat Prob. 7.65 using PSpice or MultiSim. If the...Ch. 7 - In designing a signal-switching circuit, it was...Ch. 7 - Prob. 83PCh. 7 - A capacitor with a value of 10 mF has a leakage...Ch. 7 - A simple relaxation oscillator circuit is shown in...Ch. 7 - Figure 7.146 shows a circuit for setting the...Ch. 7 - A 120-V dc generator energizes a motor whose coil...Ch. 7 - The circuit in Fig. 7.148(a) can be designed as an...Ch. 7 - An RL circuit may be used as a differentiator if...Ch. 7 - An attenuator probe employed with oscilloscopes...Ch. 7 - The circuit in Fig. 7.150 is used by a biology...Ch. 7 - To move a spot of a cathode-ray tube across the...
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