This document provides an overview of topics and potential exam questions related to semiconductors and communication systems. For semiconductors, it lists definitions, concepts, and circuit examples that could be asked about in 2-3 mark questions. These include conduction bands, band gaps, intrinsic/extrinsic semiconductors, diodes, transistors, logic gates, and oscillator circuits. For communication systems, it lists definitions, concepts, and diagrams that could be asked about in 1-3 mark questions, covering topics like propagation modes, system components, modulation techniques, and applications. The document aims to prepare students for exams on these subjects by outlining the essential information and level of understanding required to answer different types of questions.

1. Semiconductors
Total Marks 3/4
Possible questions 1,2,3 or 4 marks

2. Semiconductors
2 marks questions
Define :
1. Conduction band and valence band
2. Forbidden energy gap and classification of
elements in conductor, insulator and
semiconductor on basis of FEG.
3. Intrinsic and extrinsic semiconductors
4. P-type and n-type semiconductors
5. Acceptor impurity and donor impurity

3. Semiconductors
2 marks questions
Define :
6. p-n junction diode and barrier potentials of Si
and Ge diode.
7. Reverse bias and forward bias of junction
diode
8. Zener diode and it’s symbolic representation.
9. Solar cell and LED
10.NPN and PNP transistor
11. and  for transistors

4. Semiconductors
12.Symbolically represent AND and NOT gate
13.Symbolically represent NAND and NOR
gate
14.What are essential conditions for oscillator
circuit. (gain x Feed back factor =A. =1)
15.What do you mean by positive feedback
and negative feedback.
16.Write down Barkhausen criteria for
oscillator circuit

5. Semiconductors
1. 3 marks questions
1. What do you mean by insulator,
semiconductor and conductor. Explain
on the basis of band theory by
indicating figure.
2. Explain in details the use of diode as
half wave rectifier.
3. Explain in details the use of diode as
full wave rectifier.
4. Explain how Zener diode can be used
as voltage regulator.
5. Explain working and construction of
solar cell

6. Semiconductors
6. 3 marks questions
6. Define  and  of transistor and obtain
relation between them.
7. Represent graphically output
characteristics of transistor in common
emitter mode and define and indicate
knee voltage.
8. Explain working of common emitter
amplifier draw input output curves.
9. Explain transistor as a switch
10.Explain transistor as an amplifier.

7. Semiconductors
3 marks questions
11.Represent AND gate symbolically Draw
diode circuit for AND gate and provide its
truth table.
12.Represent NOT gate symbolically Draw
diode circuit for NOT gate and provide its
truth table.
13.Represent NAND gate symbolically Draw
diode circuit for NAND gate and provide its
truth table.

8. Semiconductors
3 marks questions
14.Represent NOR gate symbolically Draw
diode circuit for NOR gate and provide its
truth table.
15.Represent OR gate symbolically Draw
diode circuit for OR gate and provide its
truth table.

9. Semiconductors
1. 4 marks questions
1. Explain in details the circuit to study
CE characteristics and explain the
input and output characteristics using
proper graphs.
2. How will you use diode as full wave
rectifier. Explain working of full wave
rectifier in detail.

10. Communication
Total Marks 2/3
Possible questions 1,2 or 3 marks
(Chapter of definitions)

11. Communication
2 mark questions
1. Define ground wave propagation and state
factors affecting it.
2. Define sky wave propagation and state
factors affecting it.
3. Define space wave propagation and state
factors affecting it.
4. State principle of satellite communication
5. Explain how global communication is
possible by geo stationary satellite.

12. Communication
6. Define the term ( any two may be asked)
1.Signal 2.Transmitter
3.Transducer 4. Attenuation
5. Amplification 6.Noise
7. Receiver 8. Range
9.Bandwidth 10.Modulation
11.Demodulation 12.Reapeater
13. carrier wave 14. modulated wave
15. AM 16. FM 17.PM

13. Communication
7. Draw block diagram for generalized
communication system.
8. Draw block diagram for transmitter.
9. Draw block diagram for receiver.
10.Graphical representation of AM and FM
11.Mathematical expression for AM

14. Communication
3 mark questions
1. Write a short note on sky wave communication
with appropriate diagram.
2. Explain different layers in atmosphere and there
role in communication.
3. Explain different type of modulation and their
applications
4. Explain (any one may be asked)
 amplitude modulation and where it is used
 Frequency modulation and where it is used
 Phase modulation and where it is used