# JNTU previous papers | B-Tech I-Sem | Instrumentation components | November 2008

JNTU ,B.Tech I-Semester,

INSTRUMENTATION COMPONENTS, November 2008

(Electronics & Control Engineering)

SET-3

1. (a) What is the coupling mechanism with operation of a cluch in an automotive?

(b) In what way are different from chain and belt drives?

(c) Enumerate the applications of friction drives.

2. (a) What are the types characteristics of plugs used in pneumatic control valve.

(b) Explain the term valve rangeability.

3. (a) Differentiate between a potentiometer and a rheostat.

(b) What is the difference between voltage and current transducers.

(c) Mention two uses of each of current and voltage transducers.

4. (a) Discriminate between ordinary electric motors and Servo motors.

(b) Briefly explain the working of D.C and A.C servomotors with neat sketches.

5. (a) Explain the difference between transition capacitance and diffusion capacitance of a pn junction diode.

(b) Sketch the characteristics of ideal and practical diodes and explain them.

(c) Define the dynamic resistance of pn diode and explain how and why it varies

with current and temperature. Give the typical value of dynamic resistance

both for Si and Ge diodes.

6. (a) With a typical connection diagram explain the circuit operation of the adjustable positive voltage regulator LM317.

(b) Design an adjustable voltage regulator using LM317 to satisfy the following

condition: Output voltage V0 = 5 to 12V Output current I0= 1A, Adjustment

pincurrent (Iadj) for LM317 =100?A.

7. (a) Is LED a part of an optoisolatory? If so how?

(b) Generally the p material is emitter in normal diodes but in LED n material

made as emitter. Why?

(c) How is the spectral response of a LED determined and on what factor does it depend?

8. (a) Explain how a wedge filter is used as the dispersing element in a monochromator?

(b) What do you mean by resolving power of a prism? How it is controlled by the

prism materials?