JNTU, B-Tech,I-Semester Basic Electronics, November 2008


JNTU, B.Tech,I-Semester

Basic Electronics

November 2008

(Mechanical Engineering, Production Engineering and Automobile Engineering)



1. (a) Draw the atomic structure for P and N type semiconductors. Explain about minority and majority carriers.

(b) Draw Bridge rectifier circuit and explain the working of it. What are the advantages of it over the full wave rectifier with centre tapped transformer?


2. (a) Explain how the transistor acts as an amplifier

(b) Define

i. Emitter efficiency

ii. Transport factor

iii. Large signal current gain and

iv. Emitter resistance.


3. (a) An amplifier with open loop voltage gain 2000± 150 is available. It is necessary

to have an amplifier whose voltage gain varies by no more than ± 0.2 percent. Find the average transmission factor ? of the feedback network and gain with feedback Af .

(b) List five characteristics of an amplifier which are modified by negative feed back. Explain in detail.


4. (a) Compare and contrast the following timers.

i. Delay Timers

ii. Interval Timers

iii. Repeat cycle timers

iv. Reset Timers

(b) Discuss the process of resistance welding.


5. (a) Give the principle of Induction heating. What are the merits of Induction heating.

(b) Explain the application of Induction heating for

i. surface hardening of steel.

ii. Annealing of brass and iron.


6. (a) Explain magnetic deflection system employed for deflecting the beam in CRO.

Derive the expression for magnetic deflection sensitivity.

(b) Explain the need of coating the screen with fluorescent materials and list different fluorescent materials commonly used.


7. (a) What is a Microprocessor?

(b) Explain about various addressing modes of microprocessor with suitable examples.


8. (a) Explain the operation of inverted R-2R ladder D-to-A converter.

(b) An 8-bit D-to-A converter has an output voltage range of 0-2.55V. Define its resolution in two ways.

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