LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – PHYSICS
SUPPLEMENTARY EXAMINATION – JUNE 2009
PH 3502 - ELECTRONICS - I
Date & Time: 27/06/2009 / 10:00 - 1:00 Dept. No.
Max. : 100 Marks
PART A
Answer all questions. All questions carry equal marks.
(10 x 2 = 20 marks)
1. What is an ideal voltage source ?
2. State superposition theorem.
3. Explain transistor biasing.
4. Distinguish between astable and monostable multivibrator.
5. What is common mode rejection ratio?
6. When VGS of a JFETchanges from -3.1V to -3V the drain current changes from 1mA
to 1.3mA. What is the value of trans conductance?
7. Give the logic symbol of D-flip flop with truth table.
8. What is demultiplexer?
9. Mention any two applications of shift registers.
10. Write any two differences between ROM and RAM.
PART B
Answer any four questions.
(4 x 7.5 = 30 marks)
11. State and prove maximum power transfer theorem.
12. With necessary circuit diagram explain the working of class A power amplifier.
13. Solve the following simultaneous equation using an op-amp.
a) x + y = 3
b) 2x + y = 3
x–y=1
x – 2y = 4
14. Simplify using K-map
Y = F(A,B,C,D) = ∑(1,5,6,7,11,12,13,15)
15. Explain the working of a decade counter.
PART C
Answer any four questions.
(4 x 12.5 = 50 marks)
16. What are h parameters? Determine the h parameters of a transistor in the CE configuration.
17. With circuit diagram explain the working of a Wein`s bridge oscillator.
18. a) Describe the construction and working of SCR.
b) A SCR full wave rectifier supplies to a load of 100 Ω. If the peak a.c voltage
between centre tap and one end of secondary is 200V: for a firing angle of 600
Find : i) D.C. output voltage ii) load current.
19. Discuss the working of JK flip flop with truth table.
20. Explain the function of up counter and down counter. Sketch the respective wave forms.
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