B.E. DEGREE EXAMINATION.
EC 151 — ELECTRONICS ENGINEERING
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)
- Briefly describe the energy bands in solids.
- Bring out the difference between Avalanche breakdown and zener breakdown.
- Define peak inverse voltage of a diode.
- What are the conditions for a transistor to work in active region?
- Draw the CE (NPN) configuration with proper current directions.
- What are the essential circuits of an oscillator?
- What are the characteristics of an ideal Op–Amp?
- Define holding current of SCR.
- Convert the decimal 15327 to binary, octal and hexadecimal.
- Draw the symbol of OR and NAND gates and write their respective truth table.
PART B — (5 ´ 16 =80 marks)
- Describe the working of a PN junction diode, and explain its VI characteristics.
- (a) Explain the operation of MOSFET.
(b) Explain the working of UJT.
- (a) Describe the working of any LC oscillator.
(b) Draw the circuit of a bridge rectifier and explain its operation.
- (a) Explain the operation of Astable multivibrator.
(b) Draw the Integrator, Differentiator and Adder circuits using Op–Amp and explain its operation.
- (a) Write the truth table of Full adder circuit, and the corresponding Boolean expression. Draw the circuit with minimum number of gates.
(b) With the help of a block schematics, show different parts of a central processing unit and describe in detail the function of each part.