BEE BEE Bachelor of Electrical Engineering Semiconductor Devices and Electronics Questions and Answers 3

Question 1

What determines the width of the depletion region in a reverse-biased p-n junction?

Accepted Answer

Applied reverse voltage and doping concentrations

Answer

The depletion width increases with higher reverse voltage and decreases with higher doping concentrations on either side of the junction.

Question 2

In a common-emitter BJT amplifier, what is the phase relationship between the input and output signals?

Accepted Answer

180 degrees out of phase

Answer

A common-emitter amplifier inverts the signal, producing an output that is 180 degrees out of phase with the input.

Question 3

What is the dominant carrier transport mechanism in the base region of a BJT operating in the active mode?

Accepted Answer

Diffusion

Answer

In the narrow base region of a BJT, minority carriers injected from the emitter travel primarily by diffusion due to the concentration gradient.

Question 4

Which parameter of a MOSFET is defined as the ratio of change in drain current to change in gate-source voltage?

Accepted Answer

Transconductance (gm)

Answer

Transconductance (gm) measures how effectively the gate voltage controls the drain current and is defined as ∂ID/∂VGS.

Question 5

What type of recombination dominates in indirect bandgap semiconductors like silicon?

Accepted Answer

Shockley-Read-Hall recombination via trap states

Answer

In indirect bandgap semiconductors, direct radiative recombination is unlikely, so recombination occurs primarily through trap states in the bandgap via the Shockley-Read-Hall mechanism.

BEE - Bachelor of Electrical Engineering Practice Test

BEE - Bachelor of Electrical Engineering Practice Test

BEE BEE Bachelor of Electrical Engineering Semiconductor Devices and Electronics Questions and Answers 3