Semiconductors

Question 1

Which gates are referred to as universal gates?

Answer 1

NAND and NOR gates

Any logic gate can be constructed using universal gates.

Question 2

What is a p-type semiconductor?

Answer 2

Silicon or Germanium doped with trivalent impurity like Indium

Trivalent atoms add extra holes, making it p-type.
Majority charge: holes
Minority: e

Question 3

What are intrinsic and extrinsic semiconductors?

Answer 3

Intrinsic: pure semiconductor, Extrinsic: doped with trivalent or pentavalent impurities

Question 4

What is an n-type semiconductor?

Answer 4

Silicon or Germanium doped with pentavalent impurity like Arsenic

Pentavalent atoms add extra electrons, making it n-type.

Question 5

What is the bias condition for using a Zener diode as a voltage regulator?

Answer 5

Reverse bias

This condition allows the Zener voltage to remain constant.

Question 6

What are the circuit symbols for p-n-p and n-p-n transistors?

Answer 6

p-n-p and n-p-n transistor symbols

The symbols represent the arrangement of the semiconductor materials.