Operational Amplifiers MCQs

Question 1

If the input to a comparator is a sine wave, the output is a(n) _________.

Accepted Answer

rectangular wave

Answer

ramp voltage

Answer

sine wave

Answer

sawtooth wave

Question 2

Current cannot flow to ground through a(n) ________.

Accepted Answer

virtual ground

Answer

mechanical ground

Answer

ac ground

Answer

virtual short

Question 3

______ is NOT a characteristic of an ideal op-amp.

Accepted Answer

Minimum bandwidth

Answer

Infinite voltage gain

Answer

Infinite input impedance

Answer

Zero output impedance

Question 4

A virtual ground is a(n) ______ ground because this point is at zero volts.

Accepted Answer

voltage

Answer

ordinary

Answer

chassis

Answer

earth

Question 5

The resistors Rf and Ri in an op-amp circuit control ______ .

Accepted Answer

negative feedback and voltage gain

Answer

positive feedback and current gain

Answer

negative feedback and power gain

Answer

open and closed loop gain

Question 6

"Half-splitting" is

Accepted Answer

a means of isolating a problem in a circuit

Answer

a means for nuclear fuel cells to produce electricity

Answer

a means for reducing a high ac voltage to a low dc voltage

Answer

a means of limiting current in a circuit

Question 7

An oscillator whose frequency can be controlled by an input "control voltage" is called a(n) ______ .

Accepted Answer

VCO

Answer

PLL

Answer

Schmitt trigger

Answer

S-R latch

Question 8

If the voltage across a fixed value of resistance is increased five times, what does the current do?

Accepted Answer

It increases by a factor of five.

Answer

It decreases by a factor of five.

Answer

It stays the same.

Answer

Not enough information

Question 9

If doubling the voltage across a resistor doubles the current through the resistor then

Accepted Answer

the resistor value did not change

Answer

the resistor value decreased

Answer

the resistor value increased

Answer

it is impossible to determine the change in the resistor value