EC 2205 Electronics Circuits -I Part B Expected Questions | EC2205 Part B (16 Marks) Expected Important Questions for ECE - Third (3rd) Semester ...

1. Draw the circuit of a common source FET amplifier & explain its operation? (16)

2. Briefly explain the operation of aDarlingtonemitter follower and also derive an

expression for its performance measures? (16)

3. What is a differential amplifier? Explain its working in common mode operation.

Obtain its AC equivalent circuit & drive the expression for voltage gain? (16)

4. Draw the circuit diagram of a differential amplifier. Explain the operation in difference

mode and common mode? (16)

5. What are the methods to improve the CMRR of differential amplifier? Detail any two of them. (16)

6. i) What is meant by bias stability? What factors affect BJT biasing? (8)

ii)With the help of neat diagram explain the voltage divider biasing method for JFET (8)

7. i) Explain with circuit diagram the boot strappedDarlingtonemitter follower. (8)

ii) Draw the circuit diagram of self-bias circuit using CE configuration and explain

how it stabilizes operating point. (8)

8. Draw the small signal hybrid model of CE amplifier and derive the expression for its AI.AV,RI and RO. (16)

Unit-2  www.iannauniversity.com

1. Derive the expression for the CE short circuit current gain of transistor at high frequency (16)

2. i)What is the effect of Cb’e on the input circuit of a BJT amplifier at High frequencies? (8)

ii)Derive the equation for gm which gives the relation between gm, Ic and temperature. (8)

3. i) Draw the high frequency hybrid â€"Ï€ model for a transistor in the CE

configuration and explain the significance of each component. (12)

ii) Define alpha cut off frequency. (4)

4. i) Define fα,fβ and fT and state the relation between fβ and fT (8)

ii) Explain the significance of octaves and decades. (8)

5. Define unity gain frequency. Obtain the necessary relation using transistor frequency response. (16)

6. Using hybrid π model for CE amplifier. Derive an expression for its short circuit current gain. (16)

7. Explain the operation of low frequency response CE amplifier. (16)

Unit -3 www.iannauniversity.com

1. Describe in detail about the different types of distortions occur in amplifier?(16)

2. i) Explain the concept of frequency response of an amplifier? (8)

ii) Classify the amplifiers? (8)

3. With the neat sketch describe the principle of operation of RC coupled amplifier?(16)

4. Explain the operation of low frequency response CE amplifier and also discuss

the effect of bypass capacitor? (16)

5. Draw the equivalent circuit of cascaded CE stage and also derive an expression

for its performance measures? (16)

Unit -4 www.iannauniversity.com

1. Discuss the differential voltage/currentâ€"series/shunt feedback connections with

expression for gain, input resistance and output resistance. (16)

2. Draw and explain various feedback amplifier topologies? (16)

3. i) explain the operation of Hartley oscillator. (10)

ii) Find the value of inductor in the Colpitts oscillator if c1=0.2μf, c2=0.02μf

And the frequency of the oscillator is 10 kHz. .Find the required gain for

Oscillator? (6)

4. Discuss in detail the characteristics of negative feedback amplifier? (16)

5. i) Give a short note on crystal oscillator? (8)

ii) Determine the voltage gain, input and output amplifier with feedback for

Voltage series feedback having A =-100, Ri=10kΩ, Ro=20 kΩ and β= -0.1 (8)

6. With a neat circuit diagram explain the working of RC phase shift oscillator.

Derive the expression for its frequency of oscillator? (16)

7. With a neat circuit diagram explain the working of Wien bridge phase shift

oscillator. Derive the expression for its frequency of oscillator? (16)

8. With the topologies compare the four types of negative feedback amplifier?(16)

9. Draw and explain the Colpitts oscillator circuit and determine the frequency of

oscillator? (16)

Unit - 5 www.iannauniversity.com

1. i)Draw a neat circuit diagram of push-pull class-B amplifier. Explain its working.(8)

ii) For the transformer â€" coupled class A power amplifier circuit derive the expression

for its efficiency. (8)

2. Prove that the maximum efficiency of class B amplifier is 78.5%. and that of Class A

type is 50%. (16)

3. Draw the circuit of push pull class B power amplifier coupled using transformers and

explain the operation. Prove that all the even harmonics get eliminated. What is the

assumption made for this? (16)

4. i) Compare class A, class B and class C power amplifier in their performance and

efficiency. (10)

ii) Give the design procedure for heat sinks. (6)

5. What is the difference between a voltage amplifier and a power amplifier? (16)

6. Discuss the advantage and disadvantage of a complementary symmetry class b

amplifier? (16)

7. With the help of neat diagram. Explain the characteristics of class A amplifier and

also derive an expression for its efficiency and figure of merit. (16)

ALL THE BEST!!!

By 

R.Anirudhan

I ANNA UNIVERSITY TEAM