Semiconductor Electronics-Materials, Devices and Simple Circuits Mock Test – Class 12 Physics

1. The acceptor energy level in a -type semiconductor is generally shown:

2. A transistor has and . The base current is:

3. A diode terminal list mentions anode and cathode. In the usual - diode naming convention:

4. A logic circuit has output . For inputs and , the output is:

5. In a simple circuit, current and voltage are related to charge motion in different ways. The best description is:

6. For a two-input gate, the output is only when:

7. Read the circuit description below.

The lamp is more likely to glow in:

8. A small quantity of charge has magnitude . Taking the elementary charge as , the number of elementary charges represented by this magnitude is:

9. The current relation in a transistor is:

10. A solid has a very large forbidden energy gap between its valence band and conduction band. At ordinary temperature, it will most likely behave as:

11. In the band picture of an -type semiconductor, the donor level is usually located:

12. A pure silicon crystal is considered as an intrinsic semiconductor. The word intrinsic here means that the semiconductor is:

13. The initial formation of a depletion region in a - junction:

14. In a Zener voltage regulator, the series resistor is essential because it:

15. A pure semiconductor has intrinsic carrier concentration . The electron concentration and hole concentration are:

16. Use the arrangement described below.

The most suitable identification is:

17. A transistor amplifier gives an output voltage that is larger in magnitude than the input signal voltage. The device is using the transistor mainly for:

18. A device system needs output only when neither input nor input is . The suitable gate is:

19. In an intrinsic semiconductor, the conductivity is due to:

20. If the barrier potential of a - junction decreases slightly when temperature increases, the most suitable qualitative reason is:

21. A reverse-biased diode allows only a small current before breakdown mainly because this current is due to:

22. Dynamic resistance of a diode is especially useful because it measures:

23. The barrier potential of an unbiased - junction is best described as:

24. A material with a smaller band gap is used in a photodetector. Compared with a much larger band-gap material, it can respond to lower-energy photons because:

25. A pure semiconductor is cooled so much that almost no covalent bonds are broken. Its conductivity becomes very small because:

26. Use the circuit description below.

The final output is:

27. A Zener regulator has , , , and . What happens to regulation if the Zener minimum current requirement is ?

28. Using De Morgan's theorem, the expression can be obtained from gates by using:

29. Drift of charge carriers in a semiconductor is caused by:

30. A circuit designer wants an output only when a light sensor signal and an enable signal . The sensor output is from a photodiode circuit, and the final switching device is a transistor. The suitable logic relation and transistor state for are:

31. Common-emitter current gain is defined as:

32. A digital signal differs from an analog signal because a digital signal:

33. Study the charge-balance table.

The mismatched row is:

34. Consider the following statements about transistor structure.
I. An transistor has two -type regions separated by a thin -type base.
II. A transistor has two -type regions separated by a thin -type base.
III. The base is usually made thick to force all carriers to recombine before reaching the collector.
The valid statements are:

35. A load resistor is connected in a rectifier circuit mainly so that:

36. In a diode characteristic graph, different current scales are often used for forward and reverse regions because:

37. A rectifier is a circuit that converts:

38. The negative temperature coefficient of resistance of a semiconductor means that:

39. A doped semiconductor is useful in devices mainly because doping allows:

40. The emitter of a bipolar junction transistor is usually heavily doped because its main role is to:

41. A note in a circuit file says: “Apply a bias voltage across the semiconductor device before observing its current.” Here, bias voltage means:

42. A -type semiconductor is electrically neutral even though holes are majority carriers. The best explanation is:

43. A -type semiconductor has , and all acceptors are ionised. If holes dominate conduction, , and , the conductivity is closest to:

44. A photodiode has a dark current of . Under illumination, the measured reverse current becomes . The photocurrent due to light alone is:

45. In a two-input gate, one input changes from to while the other input remains . The output changes from:

46. A full-wave rectifier is supplied by an source of frequency . The frequency of the ripple pulses in the output is:

47. A solar cell has open-circuit voltage and delivers current at a certain operating point with terminal voltage . The output power at that operating point is:

48. A Zener regulator has , , , and . If the Zener is regulating, the Zener current is:

49. Consider the following statements.
I. denotes forbidden energy gap.
II. Temperature is commonly represented by .
III. The -side of a diode is called the cathode.
The valid set is:

50. Use the graph description below.

The most suitable interpretation is: