Question 1

What is the VOUT/V_INratio (expressed in dB) of an RLC series resonant circuit with the output across the inductor if the resonant frequency is 14 MHz, the source voltage is 12 V and the inductor drops 300 V? A)13.98 dB B)25 dB C)42.91 dB D)27.96 dB

Accepted Answer

The answer of What is the VOUT/V_INratio (expressed in...

Question 2

$$\text { Figure } 13 < 2$$
-If the current is  0 A  in Figure 13-2, maybe ____________
A) the capacitor is shorted
B) the resistor is open
C) the resistor has changed values to  100$\Omega$
D) the inductor is shorted

Accepted Answer

Since there is no current flowing in the circuit, the only possibility is that there is an open circuit, meaning the resistor is not allowing current to pass through.

Question 3

$$\text { Figure } 13 < 2$$
-If the resistance increases in Figure 13-2, the bandwidth ________.
A)increases
B)remains the same
C)varies
D)decreases

Accepted Answer

The answer of 
$$\text { Figure } 13 < 2$$
-If...

Question 4

If a resonant circuit has a low Q, it ________.
A)has a smallVoltage across the capacitor
B)has a Wide pass-band
C)tunes sharply
D)has a narrow pass-band

Accepted Answer

A low Q (Quality factor) in a resonant circuit indicates a wider pass-band, meaning the circuit can pass a broader range of frequencies around its resonance point. High Q circuits have narrow pass-bands and tune more sharply.

Question 5

$$\text { Figure } 13 < 1$$
-If the frequency decreases in Figure 13-1, the impedance ________ and the phase angle ________.
A)increases, increases
B)decreases, decreases
C)decreases, increases
D)increases, decreases

Accepted Answer

The answer of 
$$\text { Figure } 13 < 1$$
-If...

Question 6

What is the bandwidth of a resonant circuit if its resonant frequency is  14.2 MHz , the inductive reactance is  3.5  $\mathrm { k } \Omega$
 and the coil's resistance is  8 ohm  ?
A)  2285 Hz
B)  32.5 kHz
C)  14.2 MHz
D)  28.4 kHz

Accepted Answer

The answer of What is the bandwidth of a resonant...

Question 7

$$\text { Figure } 13 < 2$$
-At resonance, the current in Figure 13-2 is ________.
A)1.66 mA
B)10 A
C)1.66 4
D)10 mA

Accepted Answer

The answer of 
$$\text { Figure } 13 < 2$$
-At...

Question 8

$$\text { Figure } 13 < 2$$
-If the resistance decreases in Figure 13-2, the bandwidth ________.
A)decreases
B)varies
C)remains the same
D)increases

Accepted Answer

In Figure 13-2, the bandwidth is inversely proportional to the resistance. As the resistance decreases, the bandwidth decreases as well. Therefore, the best choice is A, decreases.

Question 9

$$\text { Figure } 13 < 1$$
-If the frequency decreases in Figure 13-1, the impedance initally ________ and the current initially ________.
A)decreases, increases
B)increases, increases
C)increases, decreases
D)decreases, decreases

Accepted Answer

According to the graph, as frequency decreases, the impedance also decreases. This means that it is easier for current to flow. Therefore, the current would initially increase.

Question 10

$$\text { Figure } 13 < 1$$
-To operate the circuit in Figure 13-1 below the resonant frequency, ________ the resistance and ________ the frequency.
A)do not change, decrease
B)do not change, increase
C)decrease, decrease
D)increase, increase

Accepted Answer

To operate a circuit below its resonant frequency, the resistance should not be changed, and the frequency should be decreased. This approach maintains the circuit's resistance while adjusting the frequency to below the resonant point.

Question 11

What is the resonant frequency of a tank circuit with a  50 mH  inductor and  C=256 pF  capacitor?
A)  44.5 kHz 
B)  44.5 Hz
C)  445 kHz
D)  4.45 kHz

Accepted Answer

The resonant frequency of a tank circuit is given by the formula f = 1/(2π√(LC)). Plugging in the values of L and C given, we get f = 1/(2π√(50*10^-3 * 256*10^-12)) = 44.5 kHz, which is closest to option A.

Question 12

If an LC tank circuit is operating below resonance, the circuit is ________ in nature.
A)inductive
B)capacitive
C)positive
D)resistive

Accepted Answer

When an LC tank circuit is operating below resonance, the reactance of the capacitor is greater than the reactance of the inductor, causing the circuit to behave inductively.

Question 13

If a tuned tank circuit has a very narrow bandwidth, its    is probably_________
A) very low
B) below 10
C) about 10
D) very high

Accepted Answer

The answer of If a tuned tank circuit has a...

Question 14

In a parallel resonant RLC circuit, the impedance is ________ and the total current is ________.
A)maximum. maximum
B)minimum, minimum
C)minimum, maximum
D)maximum, minimum

Accepted Answer

In a parallel resonant RLC circuit, the impedance is at its maximum because the inductive and capacitive reactances cancel each other out, leading to a condition where only the resistive element dominates. Consequently, the total current through the circuit is at its minimum, as Ohm's law (I=V/Z) dictates that current decreases as impedance increases.

Question 15

What is the power at f₁ and f₂ in a resonant circuit that delivers 120 W ? A) 84.8 W at f₁ and 60 W at f₂ B) 84.8 W C) 60 W D) 17 W at both frequencies

Accepted Answer

The answer of What is the power at f₁ ...

Question 16

$$\text { Figure } 13 < 1$$
-If the resistance decreases in Figure 13-1, the impedance ________.
A)decreases
B)becomes zero
C)remains the same
D)increases

Accepted Answer

Impedance is the combination of resistance and reactance in a circuit. If the resistance decreases, the total impedance will also decrease because there is less opposition to the flow of current in the circuit.

Question 17

$$\text { Figure } 13 < 2$$
-If the resistor shorts in Figure 13-2, the current ________.
A)increases
B)continues, but the circuit Would not be resonant
C)decreases
D)does not change

Accepted Answer

When a resistor shorts, it effectively becomes a piece of wire with zero resistance, causing the current in the circuit to increase due to the decrease in overall circuit resistance.

Question 18

What is the current in a parallel RLC circuit if its impedance is 0.22 $M \Omega , Q$ is 100 and V_S =50 V? A) 2.27 mA B) 0.0227 mA C) 22.7 mA D) 0.227 mA

Accepted Answer

The answer of What is the current in a parallel...

Question 19

$$\text { Figure } 13 < 2$$
-If the capacitor opens in Figure 13-2, the current ________.
A)remains the same
B)increases because of the inductor
C)continues to flow, but the circuitW
Ould not be resonant
D)decreases to zero

Accepted Answer

When a capacitor opens, it becomes an open circuit, and thus, no current can flow through it. As a result, the current in the circuit decreases and eventually becomes zero.

Question 20

The resonant frequency of a tank circuitW ith a 0.150 mH inductor and 300 pF capacitor is ________.
A)1.65 MHz
B)750 kHz
C)6.05 MHz
D)347 kHz

Accepted Answer

The answer of The resonant frequency of a tank circuitW...

Quiz 13: Rlc Circuits and Resonance

What is the VOUT/V_INratio (expressed in dB) of an RLC series resonant circuit with the output across the inductor if the resonant frequency is 14 MHz, the source voltage is 12 V and the inductor drops 300 V?

$\text { Figure } 13 < 2 -If the current is 0 A in Figure 13-2, maybe A) the capacitor is shorted B) the resistor is open C) the resistor has changed values to 100 \Omega D) the inductor is shorted$ $\text { Figure } 13 < 2$ -If the current is 0 A in Figure 13-2, maybe

$\text { Figure } 13 < 2 -If the resistance increases in Figure 13-2, the bandwidth . A) increases B) remains the same C) varies D) decreases$ $\text { Figure } 13 < 2$ -If the resistance increases in Figure 13-2, the bandwidth .

If a resonant circuit has a low Q, it ________.

What is the bandwidth of a resonant circuit if its resonant frequency is 14.2 MHz , the inductive reactance is 3.5 $\mathrm { k } \Omega$ and the coil's resistance is 8 ohm ?

$\text { Figure } 13 < 2 -At resonance, the current in Figure 13-2 is . A) 1.66 mA B) 10 A C) 1.66 4 D) 10 mA$ $\text { Figure } 13 < 2$ -At resonance, the current in Figure 13-2 is .

$\text { Figure } 13 < 2 -If the resistance decreases in Figure 13-2, the bandwidth . A) decreases B) varies C) remains the same D) increases$ $\text { Figure } 13 < 2$ -If the resistance decreases in Figure 13-2, the bandwidth .

What is the resonant frequency of a tank circuit with a 50 mH inductor and C=256 pF capacitor?

If an LC tank circuit is operating below resonance, the circuit is ________ in nature.

If a tuned tank circuit has a very narrow bandwidth, its is probably_________

In a parallel resonant RLC circuit, the impedance is and the total current is .

What is the power at f₁ and f₂ in a resonant circuit that delivers 120 W ?

$\text { Figure } 13 < 1 -If the resistance decreases in Figure 13-1, the impedance . A) decreases B) becomes zero C) remains the same D) increases$ $\text { Figure } 13 < 1$ -If the resistance decreases in Figure 13-1, the impedance .

$\text { Figure } 13 < 2 -If the resistor shorts in Figure 13-2, the current . A) increases B) continues, but the circuit Would not be resonant C) decreases D) does not change$ $\text { Figure } 13 < 2$ -If the resistor shorts in Figure 13-2, the current .

What is the current in a parallel RLC circuit if its impedance is 0.22 $M \Omega , Q$ is 100 and V_S =50 V?

$\text { Figure } 13 < 2 -If the capacitor opens in Figure 13-2, the current . A) remains the same B) increases because of the inductor C) continues to flow, but the circuitW Ould not be resonant D) decreases to zero$ $\text { Figure } 13 < 2$ -If the capacitor opens in Figure 13-2, the current .

The resonant frequency of a tank circuitW ith a 0.150 mH inductor and 300 pF capacitor is ________.

Quiz 13: Rlc Circuits and Resonance

What is the VOUT/VIN ratio (expressed in dB) of an RLC series resonant circuit with the output across the inductor if the resonant frequency is 14 MHz, the source voltage is 12 V and the inductor drops 300 V?

Figure 13<2\text { Figure } 13 < 2 Figure 13<2 -If the current is 0 A in Figure 13-2, maybe ____________

Figure 13<2\text { Figure } 13 < 2 Figure 13<2 -If the resistance increases in Figure 13-2, the bandwidth ________.

If a resonant circuit has a low Q, it ________.

Figure 13<1\text { Figure } 13 < 1 Figure 13<1 -If the frequency decreases in Figure 13-1, the impedance ________ and the phase angle ________.

What is the bandwidth of a resonant circuit if its resonant frequency is 14.2 MHz , the inductive reactance is 3.5 kΩ\mathrm { k } \OmegakΩ and the coil's resistance is 8 ohm ?

Figure 13<2\text { Figure } 13 < 2 Figure 13<2 -At resonance, the current in Figure 13-2 is ________.

Figure 13<2\text { Figure } 13 < 2 Figure 13<2 -If the resistance decreases in Figure 13-2, the bandwidth ________.

Figure 13<1\text { Figure } 13 < 1 Figure 13<1 -If the frequency decreases in Figure 13-1, the impedance initally ________ and the current initially ________.

Figure 13<1\text { Figure } 13 < 1 Figure 13<1 -To operate the circuit in Figure 13-1 below the resonant frequency, ________ the resistance and ________ the frequency.