GROL Amplifier and Oscillator Circuits 5

Question 1

An RF amplifier has an input signal of 2 mV and produces an output of 400 mV. What is the voltage gain?

Accepted Answer

200

Answer

20

Answer

2000

Answer

0.005

Question 2

A voltage gain of 100 expressed in decibels (dB) equals:

Accepted Answer

40 dB

Answer

20 dB

Answer

100 dB

Answer

10 dB

Question 3

For maximum power transfer between an amplifier's output and the following stage, the source impedance should be:

Accepted Answer

Equal to the load (input) impedance of the following stage

Answer

As high as possible relative to the load impedance

Answer

As low as possible relative to the load impedance

Answer

Unrelated to the following stage's input impedance

Question 4

The formula used to calculate the resonant frequency of a parallel LC tank circuit is:

Accepted Answer

f = 1 / (2π√(LC))

Answer

f = 2π√(LC)

Answer

f = LC / (2π)

Answer

f = (2π) / (√L × √C)

Question 5

A high Q factor in a tuned tank circuit indicates:

Accepted Answer

Low energy loss per cycle with narrow bandwidth and high selectivity

Answer

High energy loss per oscillation cycle

Answer

Wide bandwidth and poor frequency selectivity

Answer

High operating temperature of the coil

Question 6

If a feedback network returns 10% of an oscillator's output voltage back to the input, the minimum voltage gain required to sustain oscillation is:

Accepted Answer

10

Answer

0.1

Answer

1

Answer

100

Question 7

In a common-emitter transistor amplifier, the phase relationship between the input and output signals is:

Accepted Answer

180° out of phase — signal is inverted

Answer

In phase — 0° shift

Answer

90° lagging — like an integrator

Answer

90° leading — like a differentiator