(Electronics & Instrumentation Engineering and Electronics & Control Engineering)
1. (a) Derive the expression for efficiency of a spiral gear.
(b) Describe in detail a system which uses spiral gear. [8+8]
2. (a) Explain the principle of working and design features of pressure relief values.
(b) Explain the terms lift and capacity as applied to safety relief values. [4+4]
3. (a) In what way a pulse transformer is different from normal transformer.
(b) A square waveform is given as input to a pulse transfer, sketch the O/P wave form.
(c) Mention a few uses of pulse transformer. [6+6+4]
4. (a) Sketch the block diagram of a servo system using two phase motor and derive
its transter function. [4+4]
(b) What will be the response of the system for step input. 
5. (a) With neat sketches briefly explain the construction and working principle of
(b) What are the important specifications of varactor diode. [10+6]
6. (a) With the help of functional diagram and circuit diagram explain the monostable
operation of 555 timer.
(b) Derive the expression for time delay of a monostable multivibrator. [10+6]
7. (a) What is the essential difference between principle of operation of normal p-n
diode and a LED.
(b) Describe the working principle of light emitting diode with neat diagram.
(c) Draw the schematic representation of an optocoupler and explain its working
8. (a) Discuss the spectral transmittance characteristics of an absorption filter.
(b) What are the parameters to be observed in the design of grating.
(c) Give two types of mounting of grating and explain the importance of mount
in the grating. [6+4+6]