# The Common-Drain Amplifier MCQ’s

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

1. A Common drain amplifier is designed using fixed bias configuration, what is its input impedance?
a) RD + rd
b) RG
c) RD || rd
d) 0

2. Which of the following is true about Common Drain amplifier?
a) It has low input impedance
b) It has high output impedance
c) Infinite gain
d) Output will be same as input

3. Output Impedance of Common Drain Amplifier is______________
a) RS+rd
b) RS
c) RS || rd
d) RS||1/gm

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

5. Which of the following is true about the effects of rd in Drain amplifier?
a) rd Increases output impedance
b) rd Decreases output impedance
c) Output impedance remains the same
d) rd Increases input impedance

6. While choosing the operating conditions, the Vgs value was set lesser to Vt. What will the output if the FET is made to work as Source Follower?
a) 0
b) Same as the input
c) Same as input but phase reversed
d) Cannot be determined

7. A sine signal with period 2S has a peak of 2V at 0.5S and at 1.5 it was -2V, if this signal is applied to Common drain configured amplifier, What will be the output at t=1S?
a) 2V
b) -2V
c) 0V
d) 1V

8. Which of the following is the other name for Common Drain Amplifier?
a) Source Follower
b) Current Booster
c) Voltage booster
d) Voltage limiter

9. What will be the gain value of FET if gmo=0?
a) 0
b) 1
c) 2
d) Infinite

10. If gm=0.5mS, RS=2KΩ, determine ZO for source follower?
a) 2KΩ
b) 1KΩ
c) 3KΩ
d) 1.5KΩ