Amplifiers: Types, Characteristics, and Applications

Question 1

The voltage gain of an amplifier is defined as:

Accepted Answer

Output voltage divided by input voltage

Answer

Input voltage divided by output voltage

Answer

Change in output voltage divided by change in input voltage

Answer

Current gain multiplied by voltage gain

Question 2

In a common-emitter amplifier, the input signal is applied to which part of the transistor?

Accepted Answer

Base

Answer

Collector

Answer

Emitter

Answer

Drain

Question 3

What is the main function of a Darlington pair amplifier?

Accepted Answer

To provide high current gain

Answer

To reduce noise

Answer

To increase frequency response

Answer

To lower distortion

Question 4

What is the role of a power amplifier in an audio system?

Accepted Answer

To drive speakers

Answer

To amplify the signal from the preamplifier

Answer

To provide low-noise amplification

Answer

To filter out unwanted frequencies

Question 5

Which of the following is the correct type of amplifier that amplifies the difference between two input signals?

Accepted Answer

Differential amplifier

Answer

Common-emitter amplifier

Answer

Common-base amplifier

Answer

Operational amplifier

Question 6

What is the primary purpose of an amplifier?

Accepted Answer

To increase the voltage, current, or power of a signal

Answer

To change the frequency of a signal

Answer

To filter out noise from a signal

Answer

To convert AC signals to DC signals

Question 7

Which of the following characteristics is NOT typically associated with an ideal operational amplifier?

Accepted Answer

Finite bandwidth

Answer

Infinite input impedance

Answer

Zero output impedance

Answer

Infinite voltage gain

Question 8

Which type of feedback configuration provides the most stable and predictable behavior in an amplifier circuit?

Accepted Answer

Negative feedback

Answer

Positive feedback

Answer

No feedback

Answer

Partial feedback

Question 9

What is the main advantage of using a Darlington pair transistor configuration?

Accepted Answer

Significantly higher current gain compared to a single transistor

Answer

Lower input impedance for improved signal coupling

Answer

Increased bandwidth for faster signal processing

Answer

Reduced noise for cleaner signal amplification

Question 10

What is the key role of a bias circuit in an amplifier?

Accepted Answer

Establishing and maintaining a stable operating point for transistors

Answer

Increasing the overall gain of the amplifier

Answer

Reducing distortion caused by non-linear operation

Answer

Protecting the amplifier from overcurrent or overheating

Question 11

Which class of amplifiers operates in the linear region for the entire input signal, resulting in the least distortion?

Accepted Answer

Class A

Answer

Class B

Answer

Class C

Answer

Class D

Question 12

What is the primary purpose of utilizing a heat sink in a power amplifier?

Accepted Answer

Dissipating heat generated by the amplifier to prevent overheating

Answer

Improving the power efficiency of the amplifier

Answer

Reducing noise and interference in the amplifier

Answer

Isolating the amplifier from external power sources

Question 13

What is the purpose of a feedback loop in an amplifier circuit?

Accepted Answer

Reduces gain and improves stability

Answer

Increases gain and improves bandwidth

Answer

Provides isolation between stages

Answer

Increases power consumption and decreases efficiency

Question 14

Which of these is NOT a type of amplifier configuration?

Accepted Answer

Comparator

Answer

Common-emitter

Answer

Common-base

Answer

Cascode

Question 15

What is the primary function of an amplifier?

Accepted Answer

To increase signal strength

Answer

To decrease signal strength

Answer

To change signal frequency

Answer

To invert signal polarity

Question 16

Which parameter is used to measure the power gain of an amplifier?

Accepted Answer

Decibels (dB)

Answer

Gain-bandwidth product (GBW)

Answer

Slew rate

Answer

Input impedance

Question 17

Which of the following is NOT a disadvantage of using an operational amplifier in an amplifier circuit?

Accepted Answer

High efficiency

Answer

Low input impedance

Answer

High output impedance

Answer

Limited bandwidth

Question 18

Which of the following circuits is commonly used to amplify AC signals?

Accepted Answer

Any of the above

Answer

RC coupled amplifier

Answer

Transformer coupled amplifier

Answer

Direct coupled amplifier

Question 19

Which of the following is NOT a type of electronic amplifier?

Accepted Answer

Tank circuit

Answer

Voltage amplifier

Answer

Current amplifier

Answer

Power amplifier

Question 20

What is the primary function of a common-emitter amplifier circuit?

Accepted Answer

To amplify voltage

Answer

To amplify current

Answer

To invert the input signal

Answer

To act as a buffer

Question 21

What is the purpose of biasing in an amplifier circuit?

Accepted Answer

To establish a stable operating point

Answer

To minimize distortion

Answer

To adjust gain

Answer

To reduce noise

Question 22

What is the feedback mechanism used in an operational amplifier circuit called?

Accepted Answer

Negative feedback

Answer

Positive feedback

Answer

Open-loop feedback

Answer

Closed-loop feedback

Question 23

What is the general relationship between the gain and bandwidth of an amplifier?

Accepted Answer

As gain increases, bandwidth generally decreases.

Answer

As gain decreases, bandwidth generally increases.

Answer

Gain and bandwidth are independent of each other.

Answer

The relationship between gain and bandwidth depends on the amplifier type.

Question 24

The gain of an amplifier is defined as the ratio of:

Accepted Answer

Output voltage to input voltage

Answer

Input voltage to output current

Answer

Input current to output voltage

Answer

Output current to input current

Question 25

Which type of amplifier has the highest output power capability?

Accepted Answer

Power amplifier

Answer

Voltage amplifier

Answer

Current amplifier

Answer

Transconductance amplifier

Question 26

The input impedance of an amplifier is defined as:

Accepted Answer

The resistance seen by the input signal

Answer

The resistance seen by the output signal

Answer

The ratio of input voltage to input current

Answer

The ratio of output voltage to output current

Question 27

A common-emitter amplifier has a voltage gain of 100. If the input signal is 10 mV, what is the output signal?

Accepted Answer

10 V

Answer

1 V

Answer

100 V

Answer

1000 V

Question 28

The bandwidth of an amplifier is defined as:

Accepted Answer

The range of frequencies over which the gain is within 3 dB of the maximum

Answer

The frequency at which the gain is maximum

Answer

The frequency at which the gain is minimum

Answer

The difference between the upper and lower cutoff frequencies

Question 29

Which of the following is NOT a typical application of amplifiers?

Accepted Answer

Power Generation in Electrical Grids

Answer

Audio Signal Amplification

Answer

Industrial Control Systems

Answer

Medical Imaging Systems

Question 30

What is the most crucial factor in ensuring the stability of an amplifier circuit?

Accepted Answer

Feedback

Answer

Gain

Answer

Bandwidth

Answer

Input impedance

Question 31

To assess the stability of an amplifier circuit, which of these techniques is commonly employed?

Accepted Answer

Bode plots and root locus analysis

Answer

Kirchhoff's laws

Answer

Thevenin and Norton theorems

Question 32

Which of the following is NOT a type of amplifier circuit?

Accepted Answer

Attenuator

Answer

Inverting amplifier

Answer

Non-inverting amplifier

Answer

Power amplifier

Question 33

The voltage gain of an amplifier is defined as:

Accepted Answer

Output voltage divided by input voltage

Answer

Input voltage divided by output voltage

Answer

Current input divided by current output

Answer

Power output divided by power input

Question 34

Which of the following is an advantage of using an operational amplifier (op-amp)?

Accepted Answer

High gain and low output impedance

Answer

Low input impedance and high output impedance

Answer

Low gain and high output impedance

Answer

High input impedance and low gain

Question 35

The primary purpose of a power amplifier is to:

Accepted Answer

Increase the power of a signal

Answer

Reduce the noise of a signal

Answer

Invert the phase of a signal

Question 36

Which of the following is NOT a characteristic of an ideal amplifier?

Accepted Answer

Finite input impedance

Answer

Infinite bandwidth

Answer

High gain

Answer

Zero output impedance

Question 37

The Q-point of an amplifier is:

Accepted Answer

The operating point without any input signal

Answer

The point of minimum input voltage

Answer

The point of maximum gain

Answer

The point of maximum output voltage

Question 38

The bandwidth of an amplifier refers to:

Accepted Answer

The range of frequencies over which the gain is within a specified range

Answer

The frequency at which the gain is maximum

Answer

The frequency at which the input impedance is zero

Question 39

Which of the following applications is NOT suitable for an amplifier?

Accepted Answer

Measuring temperature

Answer

Amplifying audio signals

Answer

Driving speakers

Answer

Generating power

Question 40

The slew rate of an amplifier indicates its:

Accepted Answer

Maximum rate of change of output voltage

Answer

Maximum amplitude of output voltage

Answer

Minimum amplitude of output voltage

Question 41

Which type of amplifier is characterized by high input resistance and low output resistance?

Accepted Answer

Voltage amplifier

Answer

Current amplifier

Answer

Transconductance amplifier

Answer

Power amplifier

Question 42

Which unit is used to measure the gain of an amplifier?

Accepted Answer

Decibels (dB)

Answer

Ohms (Ω)

Answer

Amperes (A)

Answer

Volts per meter (V/m)

Question 43

Which advantage is associated with using an operational amplifier in an amplifier circuit?

Accepted Answer

High input impedance and low output impedance

Answer

Low gain and high bandwidth

Answer

High gain and low bandwidth

Answer

High input impedance and high output impedance

Question 44

A common-emitter amplifier provides a voltage gain of 50 and a current gain of 200. What is the transconductance of the transistor used?

Accepted Answer

10 mS

Answer

5 mS

Answer

2 mS

Answer

0.5 mS

Question 45

Which amplifier type is commonly used to control the speed of electric motors?

Accepted Answer

Power amplifier

Answer

Buffer amplifier

Answer

Voltage amplifier

Answer

Current amplifier

Question 46

Which of the following is NOT a type of amplifier?

Accepted Answer

Radiator

Answer

Power amplifier

Answer

Voltage amplifier

Answer

Current amplifier

Question 47

The primary function of an amplifier is to:

Accepted Answer

Increase the amplitude of a signal

Answer

Convert an analog signal to a digital signal

Answer

Reduce the noise in a signal

Answer

Change the frequency of a signal

Question 48

The voltage gain of an amplifier is defined as the ratio of:

Accepted Answer

Output voltage to input voltage

Answer

Load resistance to source resistance

Answer

Input current to output current

Answer

Output power to input power

Question 49

The frequency response of an amplifier is a plot of:

Accepted Answer

Gain or phase shift versus frequency

Answer

Bandwidth versus slew rate

Answer

Input voltage versus output current

Answer

Power consumption versus temperature

Question 50

Which of the following factors affects the slew rate of an amplifier?

Accepted Answer

Capacitance at the output node

Answer

Feedback network

Answer

Input voltage

Answer

Load resistance

Question 51

The stability of an amplifier is determined by:

Accepted Answer

Feedback network and frequency response

Answer

Voltage gain and bandwidth

Answer

Input impedance and load resistance

Answer

Power supply voltage and slew rate

Question 52

Which of the following is NOT a type of distortion in an amplifier?

Accepted Answer

Quantization distortion

Answer

Crossover distortion

Answer

Intermodulation distortion

Answer

Harmonic distortion