RR
Code No: RR312205
III B.Tech I Semester(RR) Supplementary Examinations, May/June 2009 INDUSTRIAL ELECTRONICS (Instrumentation & Control Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Enumerate the types and practical considerations of differential amplifiers. (b) Derive an expression for the output voltage of a differential amplifier.
[8+8]
2. (a) Explain the operation of a Shunt type Voltage Regulator with neat sketch. (b) Derive the expressions for series Resistance of above Voltage Regulator. (c) Design a Shunt Regulator for output voltage 9.1v IL (max) = 100mA IL (min) = 10mA Iz(knee) = 20mA Vin = 20v
[6+4+6]
3. (a) Define the short-period and long-period accuracy of a stabilizer. (b) Draw the basic voltage stabilizer circuit using nonlinear voltage divider and explain it. [8+8] 4. (a) Explain the thermal and power ratings of SCR. (b) Explain the methods of measurement of the following SCR parameters. i. Holding and latching current ii. Turn-off time iii. dV/dt and di/dt
[9+7]
5. (a) Draw the SCR protection circuit and explain how over current protection is possible from that circuit. (b) A circuit having a prospective fault current 1 kA is protected by a fuse with I 2 t rating of 100 A2 sec on a 50-Hz basis. The faulted circuit is opened in 5 msec. Calculate the peak value of the fault current. [8+8] 6. Draw and explain the simple SCR series inverter circuit employing Class A type commutation. Draw and explain the relevant waveforms. Explain its limitations. [16] 7. List out different types of resistance welding processes and explain each one using appropriate figures and also give their applications. [16] 8. (a) Explain various direct ultrasonic methods used for optical image detection (visualisation). (b) Explain how separation of mixtures is possible by ultrasonic waves. ?????
[8+8]