BJT Amplifiers and Oscillators MCQs

Question 1

Which of the following is the advantage of push pull amplifier?

Accepted Answer

All of the above

Answer

The magnetic saturation of the core by D.C. current does not occur

Answer

Cancellation of even harmonics

Answer

Can be used for class B or class AB operation

Question 2

Which of the following configurations can be used as a buffer?

Accepted Answer

CC

Answer

CE

Answer

CB

Answer

All of the above

Question 3

Negative feedback is used in audio amplifiers to

Accepted Answer

reduce distortion

Answer

increase distortion

Answer

increase gain

Answer

decrease gain

Question 4

In a RC coupled amplifier using triodes, which capacitor is preferred for coupling capacitor?

Accepted Answer

Paper

Answer

Mica

Answer

Electrolytic

Answer

Any of the above

Question 5

Typical output from a magnetic microphone is

Accepted Answer

one millivolt

Answer

1 kV

Answer

1 V

Answer

one microvolt

Question 6

In amplifiers the main source of harmonic distortion is

Accepted Answer

non-linearity in active device

Answer

defective resistors

Answer

noisy transformer

Answer

positive feedback

Question 7

AF amplifier can amplify frequencies in the range

Accepted Answer

15 Hz to 15 kHz

Answer

20 kHz to 200 kHz

Answer

200 kHz to 20 MHz

Answer

20 MHz to 20 GHz

Question 8

In push-pull amplifiers which harmonics are balanced out?

Accepted Answer

Odd harmonics

Answer

Even harmonics

Answer

Both (a) and (b)

Answer

Neither (a) nor (b)

Question 9

A class-B amplifier is biased

Accepted Answer

just at cut-off

Answer

at the mid point of load line

Answer

nearly twice cut-off

Answer

so that IB just equal lc