FREE BEE Bachelor of Electrical Engineering Semiconductor Devices and Circuits Questions and Answers

Question 1

In a Bipolar Junction Transistor (BJT) operating in the active region for amplification, which of the following describes the biasing of the emitter-base (EB) and collector-base (CB) junctions?

Accepted Answer

EB junction is forward-biased, and CB junction is reverse-biased.

Answer

EB junction is forward-biased, and CB junction is forward-biased.

Answer

EB junction is reverse-biased, and CB junction is reverse-biased.

Answer

EB junction is reverse-biased, and CB junction is forward-biased.

Question 2

A technician is designing a simple voltage regulator circuit to provide a stable 5V output from a fluctuating 9V input. Which semiconductor device is most suitable for this application, and how should it be connected in the circuit?

Accepted Answer

A Zener diode, connected in reverse bias in parallel with the load.

Answer

A Zener diode, connected in forward bias in parallel with the load.

Answer

A standard PN junction diode, connected in reverse bias in series with the load.

Answer

A Schottky diode, connected in forward bias in series with the load.

Question 3

Which of the following statements best differentiates a MOSFET from a BJT in terms of their fundamental control mechanism?

Accepted Answer

A MOSFET is a voltage-controlled device, while a BJT is a current-controlled device.

Answer

A MOSFET is a current-controlled device, while a BJT is a voltage-controlled device.

Answer

Both are voltage-controlled devices, but MOSFETs have a lower input impedance.

Answer

Both are current-controlled devices, but BJTs have a faster switching speed.

Question 4

When applying a reverse bias voltage to a standard PN junction diode that is below the breakdown voltage, what is the primary reason for the very low current flow?

Accepted Answer

The depletion region widens, creating a large potential barrier for majority carriers.

Answer

The depletion region narrows, allowing majority carriers to flow easily.

Answer

The electric field across the depletion region is neutralized.

Answer

The generation of electron-hole pairs ceases completely.

Question 5

To create an N-type semiconductor from intrinsic silicon, the silicon crystal must be doped with an element that has:

Accepted Answer

Five valence electrons, such as Phosphorus.

Answer

Four valence electrons, such as Germanium.

Answer

Three valence electrons, such as Boron.

Answer

Six valence electrons, such as Sulfur.

Question 6

In an ideal operational amplifier (Op-Amp), which two characteristics are assumed to be infinite?

Accepted Answer

Input Impedance and Open-Loop Voltage Gain

Answer

Output Impedance and Bandwidth

Answer

Common-Mode Rejection Ratio (CMRR) and Slew Rate

Answer

Power Consumption and Input Offset Voltage