# SRM University 2007 B.Tech Information Technology EC205 -- ELECTRONIC CIRCUITS - I - Question Paper

Wednesday, 30 January 2013 07:20Web

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subsequent points.

**a.**Number of diodes

**b.**Transformer necessity

**c.**PIV rating of diodes used

**d.**avg. d.

**c.**current

**e.**Ripple factor

**f.**Rectifier efficiency

8. Explain why a bridge rectifier is preferred over a centre-tap rectifier

9. Draw the circuit diagram of a full wave rectifier using

**(**centre-tap

**a)**connection and

**(**bridge connection.

**b)**10. Prove that the ripple factor of a half wave rectifier is 1.21 and that of a full

wave rectifier is 0.482.

11. What is the ripple factor value of half wave rectifier?

12. What is ripple factor value of full wave rectifier?

13. Show that the maximum rectification efficiency of a half wave rectifier is

40.6%

14. Show that the ripple factor of a full wave rectifier is 0.482.

15. Show that the maximum rectification efficiency of a full wave rectifier is

81.2%.

16. Define efficiency of a rectifier.

17. What is the efficiency value of half wave rectifier

18. What is efficiency value of full wave rectifier.

19. Explain the necessity of filter at the output of the rectifier

20. Draw the output voltage wave form of a half wave rectifier and then show the

Effect on this waveform by connecting a capacitor across the load resistance.

21. Draw the output voltage wave form of a full wave rectifier and then show the

effect on this waveform by connecting a capacitor across the load resistance.

22. What is a filter?

23. What is ripple factor?

24. What is peak inverse voltage (PIV)?

25. Write the disadvantage of half wave rectifier.

26. Compare the waveforms of half wave and full wave rectifier.

27. What is T.U.F?

28. Compare the full wave and half wave circuit.

29. Write the advantage of bridge rectifier.

30. Write the disadvantage of bridge rectifier

31. Draw the circuit of full wave centre-tap rectifier with the capacitor input filter.

32. Draw the circuit of full wave rectifier with inductor filter.

33. Draw the circuit diagram of full wave rectifier with L-section filter.

34. Write the expression of ripple factor for capacitor input filter.

35. Write the expression of ripple factor for L-section filter.

36. Write the expression of ripple factor for ? filter.

37. Draw the circuit diagram of ? filter.

38. What is the need of power supplies in the circuit?

39. What are the elements current in Linear electronic voltage regulators.

40. What is a voltage regulator?

41. What are the kinds of regulator?

42. Draw the circuit of shunt voltage regulator.

43. What is shunt voltage regulator & series voltage regulator?

44. What are the limitations of linear regulators?

45. Write the operating principle of SMPS.

46. What are the kinds of SMPS?

47. What is SCR?

48. Explain the operation of SCR.

49. Calculate the ripple factor of a ? kind filter employing 10H choke and 2

equal capacitors 16?F every and fed from a full wave rectifier. The load

resistance is 4K?. presume supply frequency of 50Hz. A half wave rectifier

operated from a 50Hz supply uses a 1000F filter capacitance connected

across the load for the rectifier. compute the minimum value of the load

resistance that can be connected across the capacitor if the percent ripple is

not to exceed 5%.

50. What is voltage regulation.

**PART B**

1. Draw the circuit diagram of half wave rectifier and discuss the operation and Derive the expressions for

**(**avg. DC load current

**a)****(**avg. DC load voltage

**b)****(**R.M.S value of load current

**c)****(**Ripple factor.

**d)****(**PIV

**e)**2. Draw the circuit diagram of full wave rectifier and discuss the operation and Derive the expressions for

**(**avg. DC load current

**a)****(**DC power output

**b)****(**R.M.S value of load current

**c)****(**Ripple factor

**d)****(**rectifier efficiency

**e)****(**PIV

**f)**3. Draw the circuit diagram of bridge rectifier and discuss the operation and derive the expressions for different parameter.

4. Draw the circuit diagram of a full wave rectifier with capacitive filter and discuss the operation. Derive the expression for ripple factor.

5. Draw the circuit diagram of a full wave rectifier with inductor filter and discuss the operation. Derive the expression for ripple factor

6. Draw the circuit diagram of a full wave rectifier with inductor filter and discuss the operation. Derive the expression for ripple factor

7. Draw the circuit diagram of a full wave rectifier with L-section filter and discuss the operation. Derive the expression for ripple factor

8. Draw the circuit diagram of a series kind transistor regulator and discuss the design procedure of such a regulator.

9. Draw the block diagrams of switched mode power supply and discuss the operation.

10. Explain the operation of a capacitive filter after a full wave rectifier.

11. What is necessity for regulation of output DC voltage in a power supply? Draw the circuit for series regulator and define its working.

12. What are the kinds of SMPS? discuss it.

13. What is SCR. discuss the DC power control using SCR.

14. What is SCR. discuss the AC power control using SCR

15. A half wave rectifier circuit feed a resistive load of 10K? through a power transformer having a step-down turns ratio of 8:1 and operated from 230V, 50 Hz A.

**C.**mains supply. presume the forward resistance of diode to be 40? and the transformer se

**c.**winding resis. as 12?. compute the max., RMS & avg., values of current, DC o/p voltage and power, eff

**i.**of rectification, and ripple factor.

16. A full wave rectifier circuit is fed from a transformer having a centre tapped secondary winding. The rms voltage from either end of secondary to centre tap is 20

**V.**if the diode forward resistance is 3? and that of the half secondary is 5?, for a load of 1K?, compute

**(**power delivered to load,

**a)****(**% regulation at full load,

**b)****(**Efficiency at full load and

**c)****(**TUF of secondary.

**d)**17. A 5K? load is fed from a bridge rectifier connected across a transformer secondary whose primary is connected to 460V, 50 Hz supply. The ratio of number of primary turns to secondary turns is 2:

**1.**compute dc load current, dc load voltage, ripple voltage and PIV rating of diode.

18. A 3K? resistive load is to be supplied with a dc voltage of 300V from ac voltage of adequate magnitude and 50Hz frequency, by full wave rectification. The LC filter is used along with the rectifier. Design the bleeder resistance, turns ratio of transformer, VA rating of transformer, PIV rating of diodes. The desired ripple factor is 0.005 and inductor to be used is to be equal to the critical valu

**e.**Determine the filter component values.

19. Determine the ripple factor of an L-type choke input filter comprising of a 10 H choke and 8?F capacitor, used with a full wave rectifier. Compare the above outcome with a simple eight ?F capacitor input filter with a load current of 50mA and also 150 m

**A.**Neglect dc resistance of choke and presume supply frequency of 50 Hz.

ques. Bank

EC 205 – Electronic Circuits – I

Earning: Approval pending. |