BEE Bachelor of Electrical Engineering Semiconductor Devices and Electronics Questions and Answers

Question 1

An N-channel enhancement-mode MOSFET (E-MOSFET) is operating with a gate-to-source voltage (VGS) equal to zero. Which of the following statements correctly describes the state of the device?

Accepted Answer

The device is in the 'OFF' state, and no significant drain current (ID) flows because no conductive channel exists between the drain and source.

Answer

The device is in the 'ON' state, and a significant drain current (ID) flows due to the pre-existing doped channel.

Answer

The device operates in the saturation region, acting as a constant current source.

Answer

The device is in a depletion mode, and a negative VGS is required to turn it off.

Question 2

Which of the following is a key characteristic of an ideal operational amplifier (op-amp)?

Accepted Answer

Infinite input impedance

Answer

Finite open-loop voltage gain

Answer

Non-zero output impedance

Answer

Finite bandwidth

Question 3

A technician is building a simple DC voltage regulator circuit. To provide a stable 5.1V output from a fluctuating 9V input source, a specific type of diode is used. How must this diode be connected in the circuit to achieve voltage regulation?

Accepted Answer

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

Answer

A Zener diode connected in series with the load and in forward-bias.

Answer

A standard rectifier diode connected in parallel with the load and in forward-bias.

Answer

A Schottky diode connected in parallel with the load and in reverse-bias.

Question 4

When a P-N junction diode is forward-biased, what is the primary effect on the depletion region and the potential barrier?

Accepted Answer

The depletion region narrows, and the potential barrier is reduced.

Answer

The depletion region widens, and the potential barrier increases.

Answer

The depletion region and potential barrier remain unchanged.

Answer

The depletion region disappears completely, and the potential barrier inverts.

Question 5

Which of the following accurately describes a key characteristic of a Bipolar Junction Transistor (BJT) amplifier in a common-emitter (CE) configuration?

Accepted Answer

A 180-degree phase shift between the input and output signals.

Answer

Low voltage gain and high input impedance.

Answer

Low current gain and low output impedance.

Answer

No phase shift between the input and output signals.

Question 6

An engineer compares a practical (real-world) op-amp to its ideal model. Which parameter, defined as the ratio of differential-mode gain to common-mode gain, is infinite in the ideal model but finite and typically measured in decibels (dB) in a practical op-amp?

Accepted Answer

Common-Mode Rejection Ratio (CMRR)

Answer

Slew Rate

Answer

Gain-Bandwidth Product

Answer

Output Impedance

An N-channel enhancement-mode MOSFET (E-MOSFET) is operating with a gate-to-source voltage (VGS) equal to zero.Which of the following statements correctly describes the state of the device?

An N-channel enhancement-mode MOSFET (E-MOSFET) is operating with a gate-to-source voltage (VGS) equal to zero.
Which of the following statements correctly describes the state of the device?