#### Frequency Variation in a Series RLC Circuit mcqs

In a series RLC circuit, the resonant frequency is determined by:

a) Resistance

b) Inductance

c) Capacitance

d) All of the above

Answer: d) All of the above

When the frequency of the applied voltage in a series RLC circuit is equal to the resonant frequency , the circuit exhibits:

a) Maximum impedance

b) Minimum impedance

c) Maximum current

d) Minimum current

Answer: a) Maximum impedance

Explanation: When the frequency of the applied voltage in a series RLC circuit is equal to the resonant frequency, the circuit exhibits maximum impedance.

The bandwidth of a series RLC circuit is defined as:

a) The range of frequencies around the resonant frequency

b) The range of frequencies below the resonant frequency

c) The range of frequencies above the resonant frequency

d) The total range of frequencies from zero to infinity

Answer: a) The range of frequencies around the resonant frequency

Explanation: The bandwidth of a series RLC circuit refers to the range of frequencies around the resonant frequency where the circuit’s response is within a specified tolerance.

In a series RLC circuit, if the frequency of the applied voltage is below the resonant frequency, the impedance is primarily determined by the:

a) Resistance

b) Inductance

c) Capacitance

d) None of the above

Answer: b) Inductance

Explanation: When the frequency of the applied voltage is below the resonant frequency in a series RLC circuit, the impedance is primarily determined by the inductance.

In a series RLC circuit, if the frequency of the applied voltage is above the resonant frequency, the impedance is primarily determined by the:

a) Resistance

b) Inductance

c) Capacitance

d) None of the above

Answer: c) Capacitance

Explanation: When the frequency of the applied voltage is above the resonant frequency in a series RLC circuit, the impedance is primarily determined by the capacitance.

The quality factor (Q-factor) of a series RLC circuit determines:

a) The sharpness of the resonance

b) The bandwidth of the circuit

c) The selectivity of the circuit

d) All of the above

Answer: d) All of the above

Explanation: The quality factor (Q-factor) of a series RLC circuit affects the sharpness of the resonance, the bandwidth, and the selectivity of the circuit.

The quality factor (Q-factor) of a series RLC circuit is calculated as the ratio of:

a) Inductive reactance to resistance

b) Capacitive reactance to resistance

c) Reactance to impedance

d) None of the above

Answer: c) Reactance to impedance

Explanation: The quality factor (Q-factor) of a series RLC circuit is calculated as the ratio of reactance to impedance.

When the frequency of the applied voltage in a series RLC circuit is below the resonant frequency, the phase angle between the current and the voltage is:

a) 0 degrees

b) Positive

c) Negative

d) 90 degrees

Answer: b) Positive

Explanation: When the requency of the applied voltage is below the resonant frequency in a series RLC circuit, the phase angle between the current and the voltage is positive.

When the frequency of the applied voltage in a series RLC circuit is above the resonant frequency, the phase angle between the current and the voltage is:

a) 0 degrees

b) Positive

c) Negative

d) 90 degrees

Answer: c) Negative

Explanation: When the frequency of the applied voltage is above the resonant frequency in a series RLC circuit, the phase angle between the current and the voltage is negative.

The resonance in a series RLC circuit occurs when:

a) The reactive components cancel each other out

b) The impedance is at its maximum

c) The circuit is inductively dominant

d) The circuit is capacitively dominant

Answer: a) The reactive components cancel each other out

Explanation: Resonance in a series RLC circuit occurs when the reactive components (inductive reactance and capacitive reactance) cancel ech other out, resulting in a minimum impedance.

The impedance of a series RLC circuit at resonance is:

a) Purely resistive

b) Purely inductive

c) Purely capacitive

d) Indeterminate

Answer: a) Purely resistive

Explanation: At resonance, the impedance of a series RLC circuit is purely resistive, meaning it has no reactive components.

The phase angle between the current and the voltage in a series RLC circuit at resonance is:

a) 0 degrees

b) 45 degrees

c) 90 degrees

d) 180 degrees

Answer: a) 0 degrees

Explanation: At resonance, the phase angle between the current and the voltage in a series RLC circuit is 0 degrees.

The resonant frequency of a series RLC circuit can be calculated using:

a) Ohm’s Law

b) Kirchhoff’s Voltage Law

c) Kirchhoff’s Current Law

d) LC resonance formula

Answer: d) LC resonance formula

Explanation: The resonant frequency of a series RLC circuit can be calculated using the LC resonance formula : f = 1 / (2π√(LC)) , where f is the resonant frequency , L is the inductance, and C is the capacitance.

The resonant frequency of a series RLC circuit is inversely proportional to:

a) Resistance

b) Inductance

c) Capacitance

d) None of the above

Answer: c) Capacitance

The bandwidth of a series RLC circuit is directly proportional to:

a) Resistance

b) Inductance

c) Capacitance

d) None of the above

Answer: a) Resistance

Explanation: The bandwidth of a series RLC circuit is directly proportional to the resistance.

When the resistance in a series RLC circuit is increased, the bandwidth:

a) Increases

b) Decreases

c) Remains the same

d) Cannot be determined

Answer: b) Decreases

Explanation: When the resistance in a series RLC circuit is increased, the bandwidth decreases, resulting in a sharper and narrower frequency response.

When the inductance in a series RLC circuit is increased, the resonant frequency:

a) Increases

b) Decreases

c) Remains the same

d) Cannot be determined

Answer: b) Decreases

Explanation: When the inductance in a series RLC circuit is increased, the resonant frequency decreases.

When the capacitance in a series RLC circuit is increased, the resonant frequency:

a) Increases

b) Decreases

c) Remains the same

d) Cannot be determined

Answer: a) Increases

Explanation: When the capacitance in a series RLC circuit is increased, the resonant frequency increases.

The reactance of the inductor in a series RLC circuit increases with:

a) Increasing frequency

b) Decreasing frequency

c) Increasing resistance

d) Decreasing resistance

Answer: a) Increasing frequency

Explanation: The reactance of an inductor in a series RLC circuit increases with increasing frequency, as the inductive effect becomes more pronounced.

The reactance of the capacitor in a series RLC circuit decreases with:

a) Increasing frequency

b) Decreasing frequency

c) Increasing resistance

d) Decreasing resistance

Answer: a) Increasing frequency

Explanation: The reactance of a capacitor in a series RLC circuit decreases with increasing frequency, as the capacitive effect becomes more dominant.