Frequency Response

1. What causes the gain of a BJT amplifier to drop at low frequencies?

• Load resistance

• Inter-electrode capacitance

• Coupling and bypass capacitors

• Collector current

What is the definition of a cutoff frequency in an amplifier's frequency response?

• Frequency where input voltage is minimum

• Frequency at which power is maximum

• Frequency where gain has dropped by 3 dB

• Frequency where current is zero

What does the bandwidth of an amplifier represent?

• Frequency range where gain is zero

• Range between the power supply limits

• Range between the lower and upper cutoff frequencies

• The total harmonic distortion range

What does a Bode plot display?

• Gain vs. input voltage

• Frequency response of an amplifier

• Voltage vs. current

• Phase angle vs. power

What type of frequency change does a –20 dB/decade roll-off indicate?

• 2-fold frequency decrease

• 5-fold frequency increase

• 10-fold frequency change

• 1% frequency shift

Which component has the most influence on the lower cutoff frequency in a BJT amplifier?

• The one with the highest cutoff frequency

• The one with the lowest reactance

• The one with the smallest capacitance

• The one with the lowest gain

What is the typical unit used for gain in a Bode plot?

• Volts

• Amperes

• Hertz

• Decibels (dB)

What is Miller capacitance in BJT and FET amplifiers related to?

• Collector current

• Inter-electrode capacitance and gain

• Base resistance

• Output resistance

At high frequencies, the gain of an amplifier decreases due to:

• Internal and stray capacitances

• Decreased resistance

• Increased power supply voltage

• Output inductance

In a multistage amplifier, the overall frequency response is primarily determined by:

• The middle stage

• The stage with the lowest gain

• The first stage only

• The highest lower cutoff frequency and the lowest upper cutoff frequency