SRM University 2007 B.Tech Information Technology ELECTRONIC DEVICES AND CIRCUITS - Question Paper

25. Define the terms dark current, diode sensitivity for a photo diode.
26. Differentiate ranging from LED and photo diode.
27. Explain why the junction depletion region in a photo diode penetrates deeply in to the N kind layer.
28. Explain how photo diode works as a photovoltaic device.
29. Explain how photo diode works as a photoconductive device.
30. Draw the V-I characteristics of a solar cell and discuss the significance of knee point in the characteristics.
31. Explain the principle of solar cell.
32. List a few of the applications of the solar cell.
33. What is short-circuited current and open-circuited voltage in a solar cell?
34. Draw the series-parallel arrangement of solar cells to function as a solar battery charger.
35. Draw the symbols of photo diode and LED
36. Explain why photo diode is reverse biased to use it as a photoconductive device.
37. What is population inversion?









TEN MARKS

1. (a) Sketch diagram to show the operation and construction of an LED. Briefly
discuss.
(b) Differentiate ranging from LED and LCD.
2. Sketch a 7 segment LED display. discuss the operation of common anode and common cathode connections.
3. Sketch the 7-segment LCD and show the waveforms involved in controlling the cells. discuss the identical.
4. Using illustrations discuss the operation of liquid crystal cells. explain the difference ranging from reflective kind and transmittive kind cells.
5. (a) discuss the operation of a solar cell and draw its characteristics.
(b) Sketch the circuit diagram of an array of solar cells employed as a battery
charger and briefly discuss.
6. Sketch the cross part of a typical photo diode and discuss its operation. Sketch typical photo diode characteristics and explain their shape.
7. Write short notes on
(i) Photoconductive device.
(ii) Photovoltaic device.
8. Explain the principle, operation and characteristics of a laser diode with a neat diagram.







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UNIT III

TWO MARKS

1. Differentiate ranging from linear and digital IC.
2. What are the 2 classifications of IC? discuss.
3. Draw the pin diagram of operational amplifier 741 and identify all the pins.
4. Write a note on packages of an op-amp?
5. Draw the basic input output stages for a bipolar opamp
6. Draw the basic input output stages for a BIFET opamp

Earning:   Approval pending.