AMCET
ELECTRONIC DEVICES AND CIRCUITS
TUTORIAL 1
1. Explain the categories of the amplifiers based on their output?
2. Explain the coupling circuits used in multistage amplifiers?
3. What are the roles of capacitors in amplifiers?
4. Advantages and disadvantages of RC coupling circuit.
5.
6.
7.
8.
What is transistor Biasing?
In which regions a transistor is used as a switch?
Why do we need coupling capacitors in the amplifiers?
In absence of signal, which one between series fed and transformer fed power
amplifier dissipates more heat. Why?
9. What is a Multi-vibrator?
10. Give example of A-stable and Bi-stable Multi-vibrator?
11. Due to the way it operates, mention the advantage of A-stable multi-vibrator.
12. What is the variable voltage regulator?
13. Mention types of multistage amplifiers due to their circuit block.
14. Differentiate between the power and voltage amplifiers?
15. Mention the features that differentiate the power transistor from other
transistors.
16. For the following Rc coupled multistage amplifier,
R
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i.
Draw the Ac equivalent circuit
ii.
Calculate the input resistance of second stage, output resistance of
first stage, output resistance of second stage, overall voltage
amplification in decibels.
Given R1=50K, R2=10K, RE=1K, RL=4.7K, Ro=20K, Vcc=24V,
β1=β2=100. Use re=50mV/IE and neglect VBE.
iii.
What is the use of coupling capacitors in the amplifier?
17. Given the power amplifier in Figure 1 with Rb=1KΩ, Rc =8Ω, Vcc =20 and β=25.
Figure 1
a.
b.
c.
d.
Calculate the input and output power of an amplifier.
[4 marks]
Calculate the efficiency of power amplifier.
[2 marks]
What is the power dissipated in the amplifier?
[2 marks]
Calculate the Impedance transformation RL’ in class A transformer fed power amplifier
for the below diagram given RL = 4Ω and N1:N2=5:1.[4 marks]
Figure 2
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