Transistors: Types, Characteristics, and Biasing - Electronics I Quiz

Question 1

In transistor biasing, which parameter is crucial?

Accepted Answer

Base-emitter voltage (Vbe)

Answer

Collector current (Ic)

Answer

Saturation current (Is)

Answer

Transconductance (gm)

Question 2

Identify a distinctive characteristic of an NPN transistor:

Accepted Answer

Majority charge carriers are electrons

Answer

Positive emitter terminal

Answer

Collector wider than base

Answer

Negative collector terminal

Question 3

In which application is a transistor commonly used as a switch?

Accepted Answer

Logic gate

Answer

Audio amplifier

Answer

Power supply regulator

Answer

Radio transmitter

Question 4

What is the primary purpose of employing a Darlington pair?

Accepted Answer

Increases current gain

Answer

Increases voltage gain

Answer

Enhances frequency response

Answer

Reduces power dissipation

Question 5

In a transistor-based flip-flop circuit, how does positive feedback help maintain the circuit's state?

Accepted Answer

Positive feedback creates a loop that strengthens the current state.

Answer

Positive feedback increases the input signal's strength.

Answer

Positive feedback provides voltage to the transistors for proper operation.

Question 6

Which type of transistor is most prevalent in electronic circuits?

Accepted Answer

NPN

Answer

PNP

Answer

FET

Answer

MOSFET

Question 7

In a bipolar junction transistor, what is the primary function of the base terminal?

Accepted Answer

Controlling current flow between the collector and emitter

Answer

Providing a collector current path

Answer

Establishing a transistor bias voltage

Answer

Limiting collector-emitter junction voltage

Question 8

What is the primary purpose of transistor biasing?

Accepted Answer

Establishing a stable operating point

Answer

Enhancing transistor gain

Answer

Reducing transistor power consumption

Answer

Safeguarding the transistor

Question 9

What is the role of a load resistor in a transistor amplifier circuit?

Accepted Answer

Providing a collector current path

Answer

Determining the transistor's operating point

Answer

Increasing circuit voltage gain

Answer

Reducing circuit power consumption

Question 10

What is the purpose of a Darlington pair?

Accepted Answer

Increasing current gain

Answer

Increasing voltage gain

Answer

Reducing noise figure

Answer

Increasing bandwidth

Question 11

The primary difference between unipolar and bipolar transistors lies in:

Accepted Answer

The type of charge carrier involved

Answer

Current gain capabilities

Answer

Biasing complexity

Question 12

Which of the following accurately describes the operation of a bipolar junction transistor (BJT)?

Accepted Answer

It is a bipolar device that conducts electricity in both forward and reverse bias conditions.

Answer

It is a unipolar device that controls current flow using only electrons.

Answer

It is a voltage-controlled device that regulates current flow based solely on its base voltage.

Answer

It is a temperature-insensitive device that exhibits minimal changes in its characteristics with temperature variations.

Question 13

What is the primary function of the base region in a BJT?

Accepted Answer

To control the flow of majority charge carriers from the emitter to the collector.

Answer

To provide a low-resistance path between the emitter and collector.

Answer

To isolate the emitter and collector regions from each other.

Answer

To store charge and amplify the input signal.

Question 14

What is the main purpose of a load resistor in a transistor amplifier circuit?

Accepted Answer

To limit the current through the transistor and stabilize the operating point.

Answer

To provide a voltage drop for biasing the transistor.

Answer

To amplify the output signal from the transistor.

Answer

To isolate the transistor from the output load.

Question 15

What is the primary application of a field-effect transistor (FET)?

Accepted Answer

Switching of electronic circuits

Answer

Amplification of electrical signals

Answer

Conversion of AC signals to DC signals

Answer

Generation of high-frequency oscillations

Question 16

Which factor has the greatest influence on the threshold voltage of a MOSFET?

Accepted Answer

Oxide thickness

Answer

Gate material

Answer

Channel doping concentration

Answer

Source-drain voltage

Question 17

What is the role of transistors in a logic gate circuit?

Accepted Answer

To perform logical operations on binary inputs

Answer

To amplify the input signal

Answer

To regulate the power supply voltage

Answer

To isolate different parts of the circuit

Question 18

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

Accepted Answer

Significantly increased current gain

Answer

Improved voltage gain

Answer

Reduced input impedance

Answer

Enhanced high-frequency operation

Question 19

Which of the following is not a type of transistor?

Accepted Answer

Diode

Answer

Bipolar Junction Transistor (BJT)

Answer

Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET)

Answer

Insulated-Gate Bipolar Transistor (IGBT)

Question 20

Which biasing technique is most suitable for maintaining a transistor in its active region?

Accepted Answer

Voltage divider bias

Answer

Fixed biasing

Answer

Emitter bias

Answer

Collector feedback bias

Question 21

The key difference between a BJT and a MOSFET lies in:

Accepted Answer

Voltage vs current control

Answer

Majority vs minority carrier operation

Answer

Gain characteristics

Answer

Susceptibility to electrostatic discharge (ESD)

Question 22

The purpose of a heat sink in a transistor circuit is to:

Accepted Answer

Dissipate heat generated by the transistor

Answer

Isolating the transistor from the circuit

Answer

Increase transistor gain

Answer

Protect against overvoltage

Question 23

A Darlington pair is used primarily to:

Accepted Answer

Increase amplifier gain

Answer

Reduce input impedance

Answer

Increase output impedance

Answer

Protect against overcurrent

Question 24

How do temperature variations impact the collector current in a bipolar junction transistor (BJT)?

Accepted Answer

Collector current falls with increasing temperature due to higher reverse saturation current and lower carrier mobility.

Answer

Collector current rises with increasing temperature.

Answer

Temperature changes have no effect on collector current.

Answer

Collector current increases linearly with increasing temperature.

Question 25

How does negative feedback affect the gain of an amplifier circuit?

Accepted Answer

Negative feedback compares the amplified output signal to the input signal, subtracting a portion of the output to reduce overall gain.

Answer

Increasing the amplifier circuit's supply voltage increases gain.

Answer

Transistors with higher beta values directly influence the gain of an amplifier circuit.

Answer

Reducing the load resistance of an amplifier circuit increases its gain.

Question 26

Which of the following accurately describes the primary function of a transistor?

Accepted Answer

To amplify or switch electrical signals

Answer

To filter out unwanted frequencies from signals

Answer

To rectify alternating current (AC) signals

Answer

To generate electrical signals

Question 27

What is the region of operation in which the transistor is non-conducting?

Accepted Answer

Cut-off region

Answer

Active region

Answer

Saturation region

Answer

Linear region

Question 28

What is the primary purpose of a heat sink in a transistor circuit?

Accepted Answer

To effectively dissipate heat generated by the transistor during operation

Answer

To improve the transistor's frequency response

Answer

To prevent voltage surges from damaging the transistor

Answer

To enhance the current gain of the transistor

Question 29

Which of the following applications is not commonly associated with the use of transistors?

Accepted Answer

Generation of electrical power

Answer

Audio amplification

Answer

Radio frequency transmission

Answer

Digital signal processing

Question 30

What are the key advantages of utilizing transistors in electronic circuits?

Accepted Answer

Compact size, low power consumption, and high reliability

Answer

Complex design and difficult manufacturing process

Answer

High cost, large size, and low efficiency

Question 31

Which of the following factors can significantly impact the performance and characteristics of a transistor?

Accepted Answer

Temperature, operating frequency, and applied voltage

Answer

Temperature only

Answer

Color, physical size, and shape

Answer

Humidity, atmospheric pressure, and light intensity

Question 32

Which of the following is **not** a type of transistor?

Accepted Answer

Diode

Answer

Metal Oxide Semiconductor Field Effect Transistor (MOSFET)

Answer

Bipolar Junction Transistor (BJT)

Answer

Field Effect Transistor (FET)

Question 33

What is the primary purpose of biasing a transistor?

Accepted Answer

To establish proper operating conditions

Answer

To reduce the noise figure

Answer

To prevent thermal runaway

Answer

To increase the current gain

Question 34

What is the fundamental difference between an NPN and a PNP transistor?

Accepted Answer

The type of majority carriers in the base region

Answer

The number of terminals

Answer

The direction of current flow

Answer

The doping levels

Question 35

An example of an application where a transistor is used as a switch is:

Accepted Answer

Flip-flop

Answer

Oscillator

Answer

Amplifier

Answer

Sensor

Question 36

What is the relationship between the collector current (IC) and the base current (IB) in a BJT operating in active mode?

Accepted Answer

IC = β × IB

Answer

IC = IB + β

Answer

IC = β / IB

Answer

IC = IB / β

Question 37

What is the main function of a transistor amplifier?

Accepted Answer

To increase the power of a signal

Answer

To store data

Answer

To convert analog signals to digital signals

Answer

To isolate different parts of a circuit

Question 38

What is the primary function of a transistor in an electronic circuit?

Accepted Answer

Amplifying or switching electrical signals

Answer

Generating electrical power

Answer

Storing electrical charge

Answer

Regulating voltage

Question 39

What is the primary role of a load resistor in a transistor amplifier circuit?

Accepted Answer

To provide a path for the collector current and determine the output voltage swing

Answer

To increase the output voltage

Answer

To reduce the input impedance

Answer

To prevent transistor saturation

Question 40

What is meant by the collector saturation voltage of a transistor?

Accepted Answer

The voltage across the collector and emitter terminals when the transistor is fully conducting

Answer

The voltage across the base and emitter terminals when the transistor is in the active region

Answer

The voltage across the collector and base terminals when the transistor is in the cutoff region

Question 41

Which of these applications primarily utilizes the switching capabilities of transistors?

Accepted Answer

Digital logic circuits

Answer

Voltage regulators

Answer

Radio frequency amplifiers

Answer

Audio amplifiers

Question 42

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

Accepted Answer

Achieving a significantly higher current gain

Answer

Lower input impedance

Answer

Reduced distortion

Answer

Wider bandwidth

Question 43

What is the primary function of a heat sink attached to a power transistor?

Accepted Answer

Dissipating excess heat generated by the transistor

Answer

Increasing the transistor's current gain

Answer

Preventing electromagnetic interference

Question 44

Which of the following statements accurately describes the operation of a transistor in an amplifier circuit?

Accepted Answer

The small input signal controls a larger output signal, resulting in signal amplification.

Answer

The transistor acts as a switch, turning the output signal on or off.

Answer

The transistor generates the output signal from scratch, without requiring an input.

Question 45

What is the primary difference between NPN and PNP transistors?

Accepted Answer

The type of charge carriers used for conduction: electrons in NPN and holes in PNP.

Answer

NPN transistors have a higher current gain than PNP transistors.

Answer

NPN transistors are used in digital circuits, while PNP transistors are used in analog circuits.

Question 46

In a common-emitter configuration, what is the relationship between the input signal applied to the base and the output signal at the collector?

Accepted Answer

The output signal is an amplified and inverted version of the input signal.

Answer

The output signal is a direct replica of the input signal.

Answer

The output signal is amplified but not inverted.

Question 47

Which of the following biasing techniques is commonly used to ensure a stable operating point for a transistor amplifier?

Accepted Answer

DC biasing

Answer

AC biasing

Answer

Self-biasing

Answer

No biasing is required for stable operation.

Question 48

What is the significance of the transistor's beta (β) parameter?

Accepted Answer

It represents the current gain, indicating the ratio of collector current to base current.

Answer

It defines the transistor's switching speed.

Answer

It determines the maximum voltage the transistor can handle.

Question 49

Consider a transistor amplifier circuit. What is the primary function of the load resistor connected to the collector?

Accepted Answer

To convert the amplified current signal into a corresponding voltage signal.

Answer

To stabilize the operating point of the transistor.

Answer

To provide a path for the input signal to flow.

Question 50

What is the main advantage of using a field-effect transistor (FET) compared to a bipolar junction transistor (BJT)?

Accepted Answer

FETs have a very high input impedance, leading to minimal loading effects on the input signal.

Answer

FETs are more efficient in terms of power consumption.

Answer

FETs are simpler to manufacture than BJTs.

Question 51

You are designing a circuit that requires a transistor to switch a large current load. Which type of transistor would be most appropriate?

Accepted Answer

Power transistor

Answer

Small signal transistor

Answer

MOSFET

Question 52

A common-emitter amplifier circuit is operating in the active region. What happens to the output signal if the base current is decreased?

Accepted Answer

The output signal amplitude decreases.

Answer

The output signal frequency decreases.

Answer

The output signal amplitude increases.

Answer

The output signal frequency increases.

Question 53

What is the main purpose of a transistor in a switching circuit?

Accepted Answer

To rapidly turn the output signal on or off in response to an input signal.

Answer

To amplify the input signal.

Answer

To generate a periodic output signal.