Question 1

What is the bandwidth of the resonant circuit if the resonant frequency is 1.42 MHz, the inductive reactance is 3.5 kΩ and the coil's resistance is 8 ohm?
A)3.25 kHz
B)1.42 MHz
C)32.5 kHz
D)2285 Hz

Accepted Answer

The bandwidth (BW) of a resonant circuit is given by BW = R / (2πL), where R is the resistance and L is the inductance. The inductive reactance (XL) is given by XL = 2πfL. Solving for L gives L = XL / (2πf). Substituting the given values, BW = 8 / (2π * (3.5kΩ / (2π * 1.42MHz))) = 3.25 kHz.

Question 2

What is the lower cut off frequency in an RLC resonant circuit if the inductive reactance is 1.2 kΩ, the resonant frequency is 22 kHz and the resistance is 60 Ω?
A)20.9 kHz
B)21.7 kHz
C)21.8 kHz
D)21.5 kHz

Accepted Answer

The answer of What is the lower cut off frequency...

Question 3

What is the total current in a parallel resonant circuit if its impedance is 0.22 MΩ, the Q is 100 and the source voltage is 100 V?
A)4.55 mA
B)0.455 mA
C)45.5 mA
D)0.0455 mA

Accepted Answer

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

Question 4

If the resonant frequency is 1 MHz and Q = 50, f1 = and f2 = .
A)0.99 MHz, 1.02 MHz
B)0.98 MHz, 1.02 MHz
C)0.99 MHz, 1.01 MHz
D)0.98 MHz, 1.01 MHz

Accepted Answer

The answer of If the resonant frequency is 1 MHz...

Question 5

In a series RLC circuit at resonance, the capacitive reactance (XC)and the inductive reactance (XL):
A)are minimum.
B)are moderate.
C)add to each other.
D)cancel each other.

Accepted Answer

At resonance in a series RLC circuit, the capacitive reactance (XC) and the inductive reactance (XL) are equal in magnitude but opposite in phase, thus they cancel each other out.

Question 6

What is the ratio of VOUT/VIN (expressed in dB)in an RLC series resonant circuit if the output voltage is taken across the inductor, the resonant frequency is 14 MHz, the source voltage is 18 V and the inductor drops 300 V?
A)14.0 dB
B)24.4 dB
C)28 dB
D)42.9 dB

Accepted Answer

The answer of What is the ratio of VOUT/VIN (expressed...

Question 7

In a parallel RLC circuit,at resonance the capacitive reactance (XC)and the inductive reactance (XL):
A)are moderate.
B)add to each to cancel current flow.
C)equal and oppose current flow.
D)are minimum.

Accepted Answer

At resonance in a parallel RLC circuit, the capacitive reactance (XC) and the inductive reactance (XL) are equal in magnitude but opposite in phase, thus they cancel each other out, resulting in minimal impedance and maximum current flow.

Question 8

In a series RLC circuit just below the resonant frequency, the impedance is:
A)at minimum.
B)more capacitive.
C)more inductive.
D)at maximum.

Accepted Answer

Just below the resonant frequency, the capacitive reactance is higher than the inductive reactance, making the circuit more capacitive.

Question 9

What is the source voltage in a series resonant circuit if VC = 150 V, VL = 150 V and VR = 50 V?
A)150 V
B)50 V
C)300 V
D)350 V

Accepted Answer

In a series resonant circuit, the source voltage (VS) is equal to the voltage across the resistor (VR) because the voltages across the inductor (VL) and capacitor (VC) cancel each other out. Therefore, VS = VR = 50 V.

Question 10

A resonant circuit with a high Q _.
A)has a very wide pass -band
B)has no pass -band
C)tunes sharply
D)has a small voltage across the capacitor

Accepted Answer

A resonant circuit with a high Q factor tunes sharply, meaning it has a narrow bandwidth and can select or reject specific frequencies more effectively.

Question 11

In a series RLC circuit at resonance:
A)the impedance is mostly resistive.
B)the impedance Z is at minimum.
C)XC equals XL and they cancel.
D)all of these.

Accepted Answer

At resonance in a series RLC circuit, the impedance is purely resistive, the impedance is at its minimum value, and the inductive reactance (XL) equals the capacitive reactance (XC), causing them to cancel each other out.

Question 12

In a series RLC circuit just above the resonant frequency, the impedance is:
A)at maximum.
B)more inductive.
C)at minimum.
D)more capacitive.

Accepted Answer

Above the resonant frequency, the inductive reactance becomes greater than the capacitive reactance, making the circuit more inductive.

Question 13

If a tuned tank circuit has a very wide bandwidth, its Q might be .
A)about 10
B)very high
C)very low
D)about 100

Accepted Answer

A wide bandwidth in a tuned tank circuit indicates a low Q factor, as Q is inversely proportional to bandwidth.

Question 14

What is the power at f1 and f2 in a resonant circuit that delivers 750 W?
A)17 W at both frequencies
B)750 W at both frequencies
C)375 W at f1 and 750 W at f2
D)375 W at both frequencies

Accepted Answer

In a resonant circuit, the power at the resonant frequency is maximum, and at the half-power frequencies (f1 and f2), the power is half of the maximum power. Therefore, at f1 and f2, the power is 375 W each, which is half of 750 W.

Question 15

The total reactance of a series RLC circuit at resonance is .
A)infinity
B)equal to the resistance
C)capacitive
D)zero

Accepted Answer

At resonance, the inductive reactance cancels out the capacitive reactance, resulting in a net reactance of zero.

Question 16

What is the resonant frequency of a tank circuit with a 150 mH inductor and a 300 pF capacitor?
A)23.7 kHz
B)237 kHz
C)2.37 MHz
D)23.7 Hz

Accepted Answer

The resonant frequency of a tank circuit is given by the formula:f = 1 / (2π√LC)where L is the inductance in henrys and C is the capacitance in farads.Plugging in the given values, we get:f = 1 / (2π√(150 mH)(300 pF)) = 23.7 kHzTherefore, the resonant frequency of the tank circuit is 23.7 kHz.

Question 17

What is the resonant impedance of a series RLC circuit with a 15 mH inductor, 0.015 µF capacitor and 80 Ω resistor?
A)15 kΩ
B)30 Ω
C)80 Ω
D)0 Ω

Accepted Answer

In a series RLC circuit, the resonant impedance is equal to the resistance, which is 80 Ω in this case.

Question 18

In an ideal parallel resonant circuit, the total current into the L and C branches is .
A)low
B)high
C)maximum
D)zero

Accepted Answer

In an ideal parallel resonant circuit, the inductive and capacitive currents are equal and opposite, canceling each other out, resulting in zero total current into the L and C branches.

Question 19

Replacing the inductor in a series resonant band -pass filter with one having a lower Q value causes the bandwidth to .
A)remain the same
B)increase
C)be more selective
D)decrease

Accepted Answer

The bandwidth of a series resonant band-pass filter is inversely proportional to the Q factor of the inductor. A lower Q value results in a wider bandwidth.

Question 20

If a tank circuit is operating above resonance, it is in nature.
A)capacitive
B)positive
C)inductive
D)resistive

Accepted Answer

Above resonance, the tank circuit behaves as a capacitive circuit because the capacitive reactance is greater than the inductive reactance.

Quiz 13: Rlccircuits and Resonance

What is the bandwidth of the resonant circuit if the resonant frequency is 1.42 MHz, the inductive reactance is 3.5 kΩ and the coil's resistance is 8 ohm?

What is the lower cut off frequency in an RLC resonant circuit if the inductive reactance is 1.2 kΩ, the resonant frequency is 22 kHz and the resistance is 60 Ω?

What is the total current in a parallel resonant circuit if its impedance is 0.22 MΩ, the Q is 100 and the source voltage is 100 V?

If the resonant frequency is 1 MHz and Q = 50, f1 = and f2 = .

In a series RLC circuit at resonance, the capacitive reactance (XC) and the inductive reactance (XL) :

What is the ratio of VOUT/VIN (expressed in dB) in an RLC series resonant circuit if the output voltage is taken across the inductor, the resonant frequency is 14 MHz, the source voltage is 18 V and the inductor drops 300 V?

In a parallel RLC circuit,at resonance the capacitive reactance (XC) and the inductive reactance (XL) :

In a series RLC circuit just below the resonant frequency, the impedance is:

What is the source voltage in a series resonant circuit if VC = 150 V, VL = 150 V and VR = 50 V?

A resonant circuit with a high Q _.

In a series RLC circuit at resonance:

In a series RLC circuit just above the resonant frequency, the impedance is:

If a tuned tank circuit has a very wide bandwidth, its Q might be .

What is the power at f1 and f2 in a resonant circuit that delivers 750 W?

The total reactance of a series RLC circuit at resonance is .

What is the resonant frequency of a tank circuit with a 150 mH inductor and a 300 pF capacitor?

What is the resonant impedance of a series RLC circuit with a 15 mH inductor, 0.015 µF capacitor and 80 Ω resistor?

In an ideal parallel resonant circuit, the total current into the L and C branches is .

Replacing the inductor in a series resonant band -pass filter with one having a lower Q value causes the bandwidth to .

If a tank circuit is operating above resonance, it is in nature.