# The Common-Source Amplifier MCQ’s

This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “The Common-Source Amplifier”.

1. An amplifier is designed using fixed bias configuration, what is its input impedance (source Resistor is un bypassed)?
a) RD+rd
b) RG
c) RD || rd
d) 0

2. Which of the following is true about the common Source amplifier?
a) It has low input impedance
b) It has high output impedance
c) Infinite gain
d) Phase reversal voltage output

3. An amplifier is designed using fixed bias configuration, what is its output impedance (source Resistor is bypassed)?
a) RD+rd
b) RG
c) RD || rd
d) 0

4. A Self bias configuration contains RD=3.3, Rs=1 KΩ, RG=1MΩ and gm=1.5mS. Determine Av?
a) -2
b) 3
c) -4
d) 5

5. A sinusoidal signal has 1.5V at t=2S, If this signal is given to Common source amplifier with |Av|=5V, what will be its output at t=2S?
a) 7.5V
b) -7.5V
c) 0
d) 15V

6. Which of the following statement is true about FET common source amplifier compared to BJT amplifier?
a) It has High input impedance
b) It has low input impedance
c) No input Voltage is needed
d) Input Voltage is needed

7. What is the reason for connecting a capacitor in parallel with Rs?
a) It blocks the noise
b) For ac signal it acts a short circuit resulting in grounding source terminal
c) It blocks the noise & for ac signal it acts a short circuit resulting in grounding source terminal
d) To increase impedance

8. For a self bias amplifier, RS=RD, the output will be_________________
a) Same as Input
b) Same as input but phase reversed
c) 0
d) Infinite

9. If gain is need to be stabilized, which of the following element is used for a Common source amplifier?
a) Capacitive
b) Inductive
c) Resistive
d) LC tank circuit

10. What is the input impedance of voltage divider configuration?
a) R1+R2
b) RG
c)
d) 0