# MOSFET Amplifier with CD Configuration – 2 MCQ’s

This set of Analog Electronic Circuits Multiple Choice Questions & Answers (MCQs) focuses on “MOSFET Amplifier with CD Configuration – 2″.

1. If g is the transconductance, r is the resistance due to channel length modulation and if M_{2} has channel length modulation but M_{1} doesn’t, what is the voltage gain at node x?

a) (1/g || r) / (1/g + (1/g || r))

b) (1/g || r) / (1/g + (1/g || 2r))

c) (1/g || r) / (2/g + (1/g || r))

d) (1/g || r) / (1/g + (2/g || r))

2. If g is the transconductance, r is the resistance due to channel length modulation and if M_{2} and M_{1} has channel length modulation but M_{3} doesn’t, what is the output resistance at the source of M_{3}?

a) 1/g || R

b) 1/g || r + 1/g

c) 1/g || R + 1/g

d) 1/g || r + 2/g

3. Can the voltage gain of a follower stage be equal to 1?

a) Yes, by increasing the transconductance

b) No

c) Yes, by modifying the bias voltage

d) Yes, by modifying the bias current

4. If g is the transconductance, r is the resistance due to channel length modulation and if M_{2} has channel length modulation but M_{1} and M_{3} doesn’t, what is the total resistance at the source of M_{2}?

a) (1/ g || R) || (1/g || r)

b) (1/ g) || (1/g || r)

c) R || (1/g || r)

d) (1/ g || R) || 1/g

5. If g is the transconductance, r is the resistance due to channel length modulation and if M2 and M1 has channel length modulation but M3 doesn’t, what is the total resistance at the drain of M2?

a) {(1 + gr)* R + R} || 2R

b) {(1 + gr)* 3R + 2R} || R

c) {(1 + gr)* (R || 1/g || r) + (R || 1/g || r)} || R

d) Infinite

6. If g is the transconductance, r is the resistance due to channel length modulation and if M2 and M1 has channel length modulation but M3 doesn’t, what is the total voltage gain for only M2?

a) g * {(1 + gr)* (R || 1/g || r) + (R || 1/g || r)} || R

b) g * {(1 + gr)* R + R} || 4R

c) g * {(1 + gr)* R + 3R} || 4R

d) g * {(1 + 2gr)* R + R} || 4R

7. The input impedance of the follower stage is ____________ than that of a CG stage.

a) greater

b) lesser

c) equal

d) cannot be compared

8. If g is the transconductance, r is the resistance due to channel length modulation and if only M3 and M2 has channel length modulation, what is the total voltage gain?

a) R/ g * {(1 + gr)* R + R} || R * R / {(1/g || r) + R

b) R/ (1/g) * g * {(1 + gr)* R + R} || R * {(1/g || r) + R

c) R/ (1/g + R) * g * {(1 + gr)* R + R} || R * R / {(1/g || r) + 3R

d) {(R || 1/g || r) / (1/g + (R || 1/g || r)} * g * [{(1 + gr)* (R || 1/g || r) + (R || 1/g || r)} ||R] * R / {(1/g || r) + R

9. Can the voltage gain of a follower stage be greater than 1?

a) Yes, by changing the transconductance

b) No

c) Yes, by changing the bias current

d) Yes, by changing the supply rail

10. The output impedance of follower is less than that of a degenerated CS stage.

a) True

b) False