59. The increase in the width of the depletion region in a p − n junction diode is due to :

58. For a p-type semiconductor, which of the following statements is true ?

57. An LED is constructed from a p-n junction diode using GaAsP. The energy gap is 1.9eV. The wavelength of the light emitted will be equal to ?

56. In a p-n junction diode, change in temperature due to heating ___ ?

55. Which one of the following represents forward bias diode ?

54. Consider the junction diode as ideal. The value of current flowing through AB is :

53. If in a p-n junction, a square input signal of 10 V is applied as shown, then the output across Rl will be :

52. In the given figure, a diode D is connected to an external resistance R = 100Ω and an e.m.f. of 3.5 V. If the barrier potential developed across the diode is 0.5 V, the current in the circuit will be :

51. The given graph represents V − I characteristic for a semiconductor device. Which of the following statement is correct?

50. The barrier potential of a p − n junction depends on:

(A) type of semi conductor material

(B) amount of doping

(C) temperature

Which one of the following is correct?

49. In a n-type semiconductor, which of the following statement is true?

48. In an unbiased p − n junction, holes diffuse from the p-region to n-region because of ___ ?

47. Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is :

47. Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is :

46. C and Si both have same lattice structure, having 4 bonding electrons in each. However, C is insulator whereas Si is intrinsic semiconductor. This is because :

46. C and Si both have same lattice structure, having 4 bonding electrons in each. However, C is insulator whereas Si is intrinsic semiconductor. This is because :

(a) In case of C the valence band is not completely filled at absolute zero temperature.

(b) In case of C the conduction band is partly filled even at absolute zero temperature.

(c) The four bonding electrons in the case of C lie in the second orbit, whereas in the case of Si they lie in the third.

(d) The four bonding electrons in the case of C lie in the third orbit, whereas for Si they lie in the fourth orbit.

Answer :  (c) The four bonding electrons in the case of C lie in the second orbit, whereas in the case of Si they lie in the third.

45. In forward biasing of the p − n junction ___ ?

44. If a small amount of antimony is added to germanium crystal ___ ?

43. In the following figure, the diodes which are forward biased, are ?

42. Pure Si at 500 K has equal number of electron (ne) and hole (nh) concentrations of 1.5 × 1016 m−3 . Doping by indium increases nh to 4.5 × 1022 m−3 . The doped semiconductor is of ?

41. A zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is ?

41. A zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is ?

40. Which one of the following statement is FALSE ?