Semiconductor Electronics Materials Devices And Simple Circuits

Step 1: Concept
The current amplification factor is defined as the ratio of collector current to base current.
Step 2: Formula
$ $
Final Answer: (D)

At room temperature, due to thermal vibrations, the few bonds of intrinsic semiconductor are broken and producing equal number of electrons and holes in the semiconductor.

Step 1: Circuit shows two NOT gates followed by a NAND gate.

Step 2: (De Morgan's law). So it is OR gate.

Step 1: For satellite in circular orbit, (since , ).

Step 2: Total energy . So (since ? Actually , so ).

Step 1: Understanding the Concept:
Total voltage = voltage across resistor + voltage across diode.
Step 2: Detailed Explanation:
V
V
Step 3: Final Answer:
Maximum voltage required V.

Step 1: Understanding the Concept:
A NAND gate produces the complement of an AND operation.
Step 2: Detailed Explanation:
By definition: NAND gate output is . By De Morgan's theorem, this is equivalent to , but the Boolean equation is .
Step 3: Final Answer:
Boolean equation: .

Step 1: Understanding the Concept:
NOR gate: output . Output is 1 only when both inputs are 0.
Step 2: Detailed Explanation:


This matches NOR gate.
Step 3: Final Answer:
The logic gate is NOR.

Step 1: Understanding the Concept:
Relation between (CB gain) and (CE gain): , so .
Step 2: Detailed Explanation:

Step 3: Final Answer:
.

Step 1: Understanding the Concept:
For a NAND gate: Output . Output is 0 only when both inputs are 1; otherwise output is 1.
Step 2: Detailed Explanation:
:
:
:
:
Step 3: Final Answer:
.

Step 1: Understanding the Concept:
A diode is forward biased when the -side is at a higher potential than the -side.
Step 2: Detailed Explanation:
Analyzing the circuit: diodes 2, 4, and 5 are forward biased.
Step 3: Final Answer:
Diodes 2, 4, and 5 are forward biased.

Step 1: Understanding the Concept:
In -type semiconductors, electrons are majority carriers.
Step 2: Detailed Explanation:
Electron concentration ( ) is greater than hole concentration ( ). Hence, it is an -type semiconductor.
Step 3: Final Answer:
The semiconductor is -type.

Step 1: Understanding the Concept:
and .
Step 2: Detailed Explanation:
. , so .
Step 3: Final Answer:
The change in collector current is .

Step 1: Understanding the Concept:
Built-in potential exists at p-n junction.
Step 2: Detailed Explanation:
Positive charge on n-side, negative on p-side creates field from n to p.
Step 3: Final Answer:
Electric field points from n-type to p-type.

Step 1: Understanding the Concept:
Holes are majority carriers in p-type semiconductors.
Step 2: Detailed Explanation:
In p-type, holes are majority charge carriers and dominate current.
Step 3: Final Answer:
p-type extrinsic semiconductors.

Step 1: Understanding the Concept:
Band structure determines conductivity.
Step 2: Detailed Explanation:
Overlapping bands means no energy gap, electrons flow freely metal.
Step 3: Final Answer:
The solid is a metal.