A source-free parallel RLC circuit has a response described by vC(t) = 80e⁻⁵⁰⁰⁰⁰ᵗ - 20e⁻²⁰⁰⁰⁰⁰ᵗ V. What was the initial capacitor voltage, vC(0+)?

Correct answer: 60 V

Explanation

The initial value of a response function is found by substituting t=0 into the complete expression. For an overdamped response v(t) = A1*e^(s1*t) + A2*e^(s2*t), the initial value is simply v(0) = A1 + A2.

Other questions

Question 1

In a source-free parallel RLC circuit, which equation is known as the characteristic equation?

Question 2

In the analysis of RLC circuits, what term is used for the quantity ω₀ = 1/√(LC)?

Question 3

A parallel RLC circuit response is characterized as overdamped under which condition?

Question 4

What is the general form of the natural response v(t) for an overdamped parallel RLC circuit?

Question 5

For a source-free series RLC circuit, how is the exponential damping coefficient, α, defined?

Question 6

A parallel RLC circuit has an inductance of 10 mH and a capacitance of 100 μF. What value of resistance R would result in an overdamped response?

Question 7

What is the general form of the natural response v(t) for a critically damped parallel RLC circuit?

Question 8

In the analogy presented between a series RLC circuit and an automotive suspension system, what does the resistance (R) correspond to?

Question 9

What is the natural resonant frequency (ωd) for an underdamped RLC circuit?

Question 10

A parallel RLC circuit has R = 6 ohms, L = 7 H, and C = 1/42 F. What are the values of s1 and s2?

Question 11

To solve for the two arbitrary constants in the response of a source-free RLC circuit, what two initial conditions are typically required?

Question 12

What is the primary role of the resistor in a source-free RLC circuit?

Question 13

A parallel RLC circuit contains a 100 ohm resistor and has parameter values α = 1000 s⁻¹ and ω₀ = 800 rad/s. What is the value of the inductance L?

Question 14

In a source-free, critically damped series RLC circuit with R = 2 kOhms and L = 1 H, what must the capacitance C be?

Question 15

The response of an RLC circuit is v(t) = 84(e⁻ᵗ − e⁻⁶ᵗ) V. What type of response is this?

Question 16

For the response v(t) = 420t*e^(-2.45t) V, what is the settling time (ts)?

Question 17

What is the primary advantage of using an op-amp circuit to create an LC-type response, as described in the section on the lossless LC circuit?

Question 18

For a series RLC circuit with L = 1 H, R = 2 kOhms, and C = 1/401 μF, what is the expected response type?

Question 19

In a source-free RLC circuit, how is the complete response composed when DC sources are present in the circuit before t=0?

Question 20

In a parallel RLC circuit with R = 100 Ω, α = 1000 s⁻¹, and ω₀ = 800 rad/s, what are the values for the complex frequencies s1 and s2?

Question 21

When determining the forced response of an RLC circuit to a DC source long after a switch has closed, how are the inductor and capacitor treated?

Question 22

In a critically damped parallel RLC circuit with v(0)=0 and i(0)=10 A, if the response is v(t) = A1*t*e^(-sqrt(6)t), what is the value of A1?

Question 23

A series RLC circuit has a response of i(t) = 2*e^(-1000t)*cos(20000t) mA. What is the value of the current at t = 0?

Question 24

In the analysis of the complete response of an RLC circuit, which step is generally the most troublesome for students?

Question 25

For a lossless LC circuit with L=4 H and C=1/36 F, the response v(t) is a pure sinusoid. What is its radian frequency?

Question 26

When comparing a series RLC circuit to its dual, a parallel RLC circuit, which parameter is calculated differently?

Question 27

In the automotive suspension analogy, what type of response corresponds to a 'stiffer shock' desirable for taking curves at high speeds?

Question 28

To achieve critical damping in a parallel RLC circuit with L = 7 H and C = 1/42 F, what must the value of the resistance R be?

Question 30

In a source-free underdamped series RLC circuit, the current is given by i(t) = e^(-αt)*(B1*cos(ωd*t) + B2*sin(ωd*t)). If the initial current i(0) is zero, what can be concluded about the constants B1 and B2?

Question 31

What is the term for the ratio of the neper frequency (α) to the resonant frequency (ω₀), often designated by ζ (zeta)?

Question 32

How many initial conditions are required to find the unique natural response of an RLC circuit?

Question 33

In the overdamped response v(t) = A1*e^(s1*t) + A2*e^(s2*t), if |s2| > |s1|, which term dominates the response for large values of time?

Question 34

A series RLC circuit is driven by DC sources. The initial conditions are i_L(0-) = 5A and v_C(0-) = 150V. What are the values of i_L(0+) and v_C(0+)?

Question 35

To select a value for R1 to make the circuit in Fig. 9.12 critically damped for t > 0, given L=4H and C=1nF, what value should be chosen?

Question 36

An underdamped parallel RLC circuit has α = 2 s⁻¹ and ω₀ = sqrt(6) s⁻¹. What is the natural resonant frequency, ωd?

Question 37

For a series RLC circuit with R=2kΩ, L=1H, C=1/401μF, i(0)=2mA and vC(0)=2V, what is the value of the constant B2 in the response i(t) = e⁻¹⁰⁰⁰ᵗ(B1cos(20000t) + B2sin(20000t))?

Question 38

If a circuit's response contains the term t * e^(-αt), what can be concluded about its damping?

Question 39

In the summary of the solution process, what is the first decision to be made when analyzing a simple three-element RLC circuit?

Question 40

For the RLC circuit in Example 9.9 with a 4A source active for t>0, what is the inductor voltage vL(0+)?

Question 41

What is the primary characteristic of a lossless LC circuit's natural response?

Question 42

In a source-free parallel RLC circuit, if R = 10.5 Ω, L = 7 H, and C = 1/42 F, what is the response type?

Question 43

What is the initial capacitor current iC(0) for a parallel RLC circuit with vC(0) = 60V, iL(0) = -0.3A, and R = 200Ω?

Question 44

For the series RLC circuit in Example 9.9, what is the value of the first derivative of the inductor current, diL/dt, at t=0+?

Question 45

In the automotive suspension analogy, a slightly underdamped response is considered preferable for which driving condition?

Question 46

For a capacitor current given by iC(t) = 2e⁻²ᵗ - 4e⁻ᵗ A, what is the settling time (ts)?

Question 47

What is the general form of the natural response for an underdamped parallel RLC circuit?

Question 48

A parallel RLC circuit has L=7H, C=1/42 F. The circuit is critically damped. The initial voltage is v(0)=0 and the initial inductor current is i(0)=10 A. What is the maximum voltage value reached?

Question 49

In the summary Table 9.1, what is the formula for the neper frequency α for a series RLC circuit?

Question 50

Why is it considered 'essentially impossible' to construct a parallel RLC circuit that is exactly critically damped in practice?