Resonance in AC Circuits Selectivity mcq
Selectivity is a measure of:
a) How sharp the frequency response of a circuit is
b) The total resistance in a circuit
c) The voltage gain of a circuit
d) The power dissipation in a circuit
Answer: a) How sharp the frequency response of a circuit is
Explanation: Selectivity refers to how well a circuit can pass a specific range of frequencies while attenuating others.
The selectivity of a circuit is determined by its:
a) Resistance
b) Inductance
c) Capacitance
d) Bandwidth
Answer: d) Bandwidth
Explanation: The selectivity of a circuit is determined by its bandwidth , which is the range of frequencies over which the circuit can effectively operate.
A highly selective circuit has a:
a) Narrow bandwidth
b) Wide bandwidth
c) Low resistance
d) High resistance
Answer: a) Narrow bandwidth
Explanation: A highly selective circuit has a narrow bandwidth, meaning it can pass a specific range of frequencies while attenuating others outside that range.
Q-factor is a measure of:
a) Selectivity
b) Bandwidth
c) Resistance
d) Power factor
Answer: a) Selectivity
The higher the Q-factor of a circuit, the:
a) More selective the circuit
b) Less selective the circuit
c) Wider the bandwidth
d) Lower the resistance
Answer: a) More selective the circuit
Explanation: A higher Q-factor indicates a more selective circuit, meaning it has a narrower bandwidth and can pass a specific range of frequencies more effectively.
Bandwidth and selectivity are:
a) Inversely proportional
b) Directly proportional
c) Unrelated
d) Indeterminate
Answer: a) Inversely proportional
Explanation: Bandwidth and selectivity are inversely proportional. A circuit with a wider bandwidth will have lower selectivity, and vice versa.
The selectivity of a circuit can be improved by:
a) Increasing the resistance
b) Decreasing the resistance
c) Increasing the inductance
d) Decreasing the inductance
Answer: c) Increasing the inductance
The quality factor ( Q-factor) of a resonant circuit is a measure of its:
a) Selectivity
b) Bandwidth
c) Resistance
d) Voltage gain
Answer: a) Selectivity
Explanation: The quality factor (Q-factor) of a resonant circuit is a measure of its selectivity, indicating how well it can pass a specific range of frequencies.
The bandwidth of a circuit can be calculated by dividing the:
a) Resonant frequency by the quality factor
b) Quality factor by the resonant frequency
c) Total resistance by the inductance
d) Capacitance by the resistance
Answer: a) Resonant frequency by the quality factor
Explanation: The bandwidth of a circuit can be calculated by dividing the resonant frequency by the quality factor.
The selectivity of a circuit is dtermined by its ability to:
a) Amplify the input signal
b) Attenuate unwanted frequencies
c) Generate a high output power
d) Sustain a stable oscillation
Answer: b) Attenuate unwanted frequencies
Explanation: The selectivity of a circuit is determined by its ability to attenuate unwanted frequencies while passing the desired frequency range.
A bandpass filter is an example of a circuit with:
a) High selectivity
b) Low selectivity
c) Wide bandwidth
d) Low resistance
Answer: a) High selectivity
Explanation: A bandpass filter is designed to pass a specific range of frequencies while attenuating frequencies outside that range, making it a highly selective circuit.
A circuit with low selectivity is commonly referred to as:
a) Wideband
b) Narrowband
c) High-Q
d) Low-Q
Answer: a) Wideband
Explanation: A circuit with low selectivity is commonly referred to as a wideband circuit since it can pass a wide range of frequencies.
The selectivity of a circuit is typically represented by its:
a) Q-factor
b) Voltage gain
c) Power factor
d) Impedance
Answer: a) Q-factor
Explanation: The Q-factor of a circuit is often used to represent its selectivity, indicating how sharp or narrow its frequency response is.
A resonant circuit with a high Q-factor exhibits:
a) High selectivity
b) Low selectivity
c) Wide bandwidth
d) High resistance
Answer: a) High selectivity
Explanation: A resonant circuit with a high Q-factor exhibits high selectivity, meaning it can pass a specific range of frequencies effectively while attenuating others.
The selectivity of a circuit is important in applications where:
a) Signal amplification is required
b) Power consumption is a concern
c) Frequency filtering is necessary
d) Voltage regulation is needed
Answer: c) Frequency filtering is necessary
Explanation: Selectivity is particularly important in applications where frequency filtering is required, such as in communication systems or audio signal processing.
The selectivity of a circuit can be described as its ability to:
a) Maintain a stable oscillation
b) Produce a high output voltage
c) Reject unwanted frequencies
d) Generate a low internal resistance
Answer: c) Reject unwanted frequencies
Explanation: The selectivity of a circuit refers to its ability to reject or attenuate unwanted frequencies while allowing the desired frequencies to pass.
The selectivity of a circuit is determined by the:
a) Gain bandwidth product
b) Impedance mismatch
c) Power factor correction
d) Shape of the frequency response curve
Answer: d) Shape of the frequency response curve
Explanation: The selectivity of a circuit is determined by the shape of its frequency response curve, which indicates its ability to pass or attenuate specific frequencies.
A circuit with a steep roll-off in its frequency response curve exhibits:
a) High selectivity
b) Low selectivity
c) Wide bandwidth
d) High resistance
Answer: a) High selectivity
Explanation: A circuit with a steep roll-off in its frequency response curve exhibits high selectivity, indicating a sharp transition between the passband and the stopband.
A circuit with a flat frequency response curve indicates:
a) Low selectivity
b) High selectivity
c) Wide bandwidth
d) Low resistance
Answer: a) Low selectivity
Explanation: A circuit with a flat frequency response curve indicates low selectivity since it does not exhibit a sharp transition between the passband and the stopband.
The selectivity of a circuit can be improved by:
a) Adding a resistance in series
b) Adding a capacitor in parallel
c) Adding an inductor in series
d) Increasing the voltage gain
Answer: c) Adding an inductor in series
Explanation: Adding an inductor in series with a circuit can improve its selectivity by narrowing the bandwidth and attenuating frequencies outside the desired range.