ISCET Semiconductor Device Principles 2

Question 1

What is the primary effect of increasing temperature on the reverse saturation current (I₀) of a silicon diode?

Accepted Answer

I₀ approximately doubles for every 10°C rise

Answer

Reverse saturation current approximately doubles for every 10°C increase in temperature due to increased minority carrier generation.

Question 2

In a PNP bipolar junction transistor operating in active mode, the emitter current is 10 mA and the base current is 0.2 mA. What is the collector current?

Accepted Answer

9.8 mA

Answer

By KCL, IC = IE – IB = 10 mA – 0.2 mA = 9.8 mA.

Question 3

Which semiconductor parameter defines the average time a minority carrier exists before recombining?

Accepted Answer

Minority carrier lifetime

Answer

Minority carrier lifetime (τ) is the average time a minority carrier survives before recombining with a majority carrier.

Question 4

A Zener diode is used primarily in which region of its V-I characteristic?

Accepted Answer

At the Zener breakdown voltage

Answer

Zener diodes are designed to operate at the reverse breakdown (Zener) voltage, maintaining a stable reference voltage.

Question 5

What is the typical value of the Early voltage (VA) for a small-signal BJT, and what does a larger VA indicate?

Accepted Answer

Typically 50–200 V; larger VA means higher output resistance and less channel-length modulation

Answer

Early voltage is typically 50–200 V for BJTs; a higher VA means the output characteristics are more horizontal, indicating higher output resistance.

(ISCET) International Society of Certified Electronics Technicians Practice Test

(ISCET) International Society of Certified Electronics Technicians Practice Test

ISCET Semiconductor Device Principles 2