1. The early effect in a bipolar junction transistor is caused by
Correct answer: (C)
large collector-base reverse bias
2. MOSFET can be used as a
Correct answer: (B)
voltage controlled capacitor
3. Thermal runaway is not possible in FET because as the temperature of FET increases
Correct answer: (A)
the mobility decreases
4. A source follower using an FET usually has a voltage gain which is
Correct answer: (A)
greater than +100
5. A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by
Correct answer: (A)
2
6. The approximate input impedance of the OPAMP circuit which has Ri=10k,Rf=100k,RL=10k
Correct answer: (D)
10k
7. An OPAMP has a slew rate of 5 V/μ S .The largest sine wave O/P voltage possible at a frequency of 1MHZ is
Correct answer: (D)
5/2 volts
8. A change in the value of the emitter resistance Re in a differential amplifier
Correct answer: (B)
affects the common mode gain Ac
9. A differential amplifier is invariably used in the i/p stage of all OP-AMPs.This is dome basically to provide the OP-AMPs with a very high
Correct answer: (A)
CMRR
10. The effective channel length of a MOSFET in a saturation decreases with increase in
Correct answer: (B)
drain voltage