BJT Amplifiers and Oscillators MCQs

Question 1

An oscillator produces oscillations due to

Accepted Answer

positive feedback

Answer

negative feedback

Answer

partly postive and partly negative

Answer

neither positive nor negative

Question 2

In order to sustain oscillations in an oscillator

Accepted Answer

both (a) and (b)

Answer

phase shold be 00

Answer

feedback factor should be unity

Answer

feedback should be negative

Question 3

In an oscillator gain stability is usually achieved by

Accepted Answer

controlling the gain

Answer

using negative feedback

Answer

using low-Q circuit

Answer

incorporating a tuned circuit

Question 4

In an oscillator circuit that uses a tapped coil in the tuned circuit is

Accepted Answer

Hartley

Answer

Armstrong

Answer

Colpitts

Answer

multivibrator

Question 5

The ____ oscillator uses tapped capacitors in the tuned circuit.

Accepted Answer

Colpitts

Answer

Armstrong

Answer

Hartley

Answer

None of the above

Question 6

By using which of the following methods the frequency stability in an oscillator can be achieved?

Accepted Answer

By incorporating a tuned circuit

Answer

By adjusting the phase shift

Answer

By employing automatic biasing

Answer

By controlling its gain

Question 7

Which of the following statements is correct regarding the Wien-bridge oscillator?

Accepted Answer

It is a stable sine-wave audio generator

Answer

It is also called sine-cosine oscillator

Answer

It is a squiire wave generator

Answer

It is a free-running oscillator

Question 8

Which of the following oscillators has best frequency stability?

Accepted Answer

Crystal

Answer

Multivibrator

Answer

Phase-shift circuit

Answer

Clapp

Question 9

The most stable sine wave oscillator with most simple circuit is

Accepted Answer

crystal

Answer

phase-shift circuit

Answer

colpitts

Answer

Armstrong