Biju Patnaik University of Technology 2008 B.Tech Computer Science and Engineering Second semester - - Question Paper

BASIC ELECTRONICS
FULL MARK-70
TIME-3HR
ans ques. no. one which is compulsory and any four from the rest.
1.Answer the subsequent questions: 6*5

(a) describe mobility and conductivity of an intrinsic semiconductor.
(b) A diode has a reverse saturation current of 5mA at 25 C for a reverse voltage of 20V. compute the reverse resistance.
(c) An ideal P-N junction diode acts like a disable switch. Justify.
(d) describe ac load line and dc load line of a npn transistor connected in CE configuration.
(e) How emitter bypass capacitor in a CE amplifier prevents signal degeneration?

2. elaborate crystal oscillators ? write their characteristics features. List 2 applications. 2+4+4
3. explain AD and DA conversion techniques used in digital in digital communication. 10
4. Draw a simplified fibre optic communication system. discuss the principle of operation. 5+5
5. Draw the circuit for CMOS logic inverter. discuss the flow of current and power. 5+5
6. What is enhancement mode of n-channel MOSFET ? 10
7. Draw the circuit of an emitter follower. Derive an expression for its output impedance. List 2 applications of an emitter follower.

Earning:   Approval pending.