1. ELL100: INTRODUCTION TO ELECTRICAL ENGG.
Course Instructors:
J.-B. Seo, S. Srirangarajan, S.-D. Roy, and S. Janardhanan
Department of Electrical Engineering, IITD

2. Ability to conduct electricity
Insulator
Material
Resistivity
Conductivity
Glass
Sulphur
Quartzfused
Conductor
Material
Resistivity
Conductivity
Silver
Copper
Aluminium

3. Ability to conduct electricity
Insulator
Material
Resistivity
Conductivity
Glass
Sulphur
Quartzfused
Conductor
Material
Resistivity
Conductivity
Silver
Copper
Aluminium

4. Ability to conduct electricity
Insulator
Material
Resistivity
Conductivity
Glass
Sulphur
Quartzfused - - - - - - - - - - -
Conductor
Material
Resistivity
Conductivity
Silver
Copper
Aluminium - - - - - - - - - - - - - - - - - - - - - - -

5. Ability to conduct electricity
Semiconductor
Material
Resistivity
Conductivity
Germanium
Silicon - - - - - - - - - - -

6. Ability to conduct electricity
Semiconductor
Material
Resistivity
Conductivity
Germanium
Silicon - - - - - - - - - - -
External energy

7. Ability to conduct electricity
Semiconductor
Material
Resistivity
Conductivity
Germanium
Silicon - - - - - - - - - - -
External energy

8. Drift current of Intrinsic semiconductor

9. Drift current of Intrinsic semiconductor

10. Drift current of Intrinsic semiconductor

11. Drift current of Intrinsic semiconductor

12. Drift current of Intrinsic semiconductor

13. Doped Semiconductor
n-type

14. Doped Semiconductor
p-type
n-type

15. Doped Semiconductor Recombination In a semiconductor,
the mobile electrons and holes tend to recombine and disappear
The rate of recombination
For the doped and intrinsic semiconductors,

16. Doped Semiconductor Recombination In a semiconductor,
the mobile electrons and holes tend to recombine and disappear
The rate of recombination
For the doped and intrinsic semiconductors,

17. Doped Semiconductor Recombination In a semiconductor,
the mobile electrons and holes tend to recombine and disappear
The rate of recombination
For the doped and intrinsic semiconductors, we have

18. Doped Semiconductor Conductivity of dopped semiconductor
In a typical n-type material, donor atoms provide a mobile electron concentration
Using
Increasing reduces
Conductivity of the doped semiconductor is determined by the doping concentration

19. Doped Semiconductor Conductivity of dopped semiconductor
In a typical n-type material, donor atoms provide a mobile electron concentration
Using
Increasing reduces
Conductivity of the doped semiconductor is determined by the doping concentration

20. Doped Semiconductor Conductivity of dopped semiconductor
In a typical n-type material, donor atoms provide a mobile electron concentration
Using
Increasing reduces
Conductivity of the doped semiconductor
is determined by the doping concentration

21. Doped Semiconductor Diffusion current
Non-uniform concentration of electric charges
enables the charges to move from a high concentrated region to a low one.

22. Doped Semiconductor Diffusion current
Non-uniform concentration of electric charges
enables the charges to move from a high concentrated region to a low one.

23. Doped Semiconductor Diffusion current
Non-uniform concentration of electric charges
enables the charges to move from a high concentrated region to a low one.
The diffusion current crossing a unit:

24. Doped Semiconductor Total current in a semiconductor Diffusion current
Drift current
Diffusion current movement caused by variation in the carrier (hole or carrier) concentration
Drift current movement caused by electric fields.
Direction of the diffusion depends on the slope of the carrier concentration
Direction of the drift current is always in the direction of the electric field.
Total current in a semiconductor

25. Doped Semiconductor Total current in a semiconductor Diffusion current
Drift current
Diffusion current movement caused by variation in the carrier (hole or carrier) concentration
Drift current movement caused by electric fields.
Direction of the diffusion depends on the slope of the carrier concentration
Direction of the drift current is always in the direction of the electric field.
Total current in a semiconductor

26. Doped Semiconductor Total current in a semiconductor Diffusion current
Drift current
Diffusion current movement caused by variation in the carrier (hole or carrier) concentration
Drift current movement caused by electric fields.
Direction of the diffusion depends on the slope of the carrier concentration
Direction of the drift current is always in the direction of the electric field.
Total current in a semiconductor

27. Doped Semiconductor Total current in a semiconductor Diffusion current
Drift current
Diffusion current movement caused by variation in the carrier (hole or carrier) concentration
Drift current movement caused by electric fields.
Direction of the diffusion depends on the slope of the carrier concentration
Direction of the drift current is always in the direction of the electric field.
Total current in a semiconductor

28. Doped Semiconductor
n-type
p-type

29. p-n Junction + + + + + + + + + + + + + + + + + + + + + + + + + + + + +— — — — — — — + + + + + + + + + + + — — — — + — + — — — + + — + — — — + + — — + + + + + — — + — + + + — — + + + — — — — — — + + + + — + + — — — — + — + + — — + + + + — — + + — + — — — + + + + + + + + — + — — + + — — + — + — — — — — + — + + + + — + — — — + + + + + — — —

30. p-n Junction + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Free moveable charges recombine => Depletion region — — — — — — — + + + + + + + + + + + + — — — — — — — + + + — + — — — + — — + + + + + — — + — + + + + + + + — — — — — + + + + — + + + + — + + — + — — — — — + — + + — + + — — + + + + + + + + — + — + — — — — — + + + + — + + + + — — + + + + — — + + — — — —
Potential difference = built-in potential

31. p-n Junction — +

32. p-n Junction — +

33. p-n Junction — +

34. p-n Junction — +

35. p-n Junction Reverse bias — — — — — — — + + + + + + + — — — — — — + +

36. p-n Junction — +

37. p-n Junction Forward bias — — — — + + + + — — — + + + — — — — — — + +

38. p-n Junction Forward bias — — + + + + — — — — — + + + — — — — — — + +
The direction of current flow is opposite to electron-flow
Forward bias — — + + + + + + — — — — — — — + + + — — — — — — + + + + + + + — — — — — — + + + + + + + — — — — — — + + + + + + +

39. Diode

40. Diode

41. Circuit with diode – 1

42. Circuit with diode – 1
Turn-on voltage

43. Circuit with diode – 1

44. Circuit with diode – 1

45. Circuit with diode – 1

46. Circuit with diode – 1

47. Circuit with diode – 1

48. Circuit with diode – 1

49. Circuit with diode – 2

50. Circuit with diode – 2

51. Circuit with diode – 2

52. Circuit with diode – 2

53. Circuit with diode – 3 – +

54. Circuit with diode – 3 – +

55. Circuit with diode – 3 – + + –

56. Circuit with diode – 4 + + – –

57. Circuit with diode – 4 + + – –

58. Circuit with diode – 4 + + – –

59. Circuit with diode – 4 + + – –

60. Circuit with diode – 4 + + – –

61. Circuit with diode – 3 (p. 96)

62. Circuit with diode – 3 (p. 96)

63. Circuit with diode – 3 (p. 96)

64. Diode: Full-wave rectifier

65. Diode: Full-wave rectifier

66. Diode: Full-wave rectifier

67. Diode: Capacitor filter
By initial charges in the capacitor
During the positive half cycle,
the source voltage increases and the capacitor discharges

68. Diode: Capacitor filter
By initial charges in the capacitor
During the positive half cycle, if the source voltage is greater than the capacitor voltage
the diode will conduct, and the capacitor charges rapidly (C is small)
As the input starts to go negative, the diode turns off
and the capacitor will slowly discharge through the load

69. Diode: Capacitor filter
By initial charges in the capacitor
During the positive half cycle, if the source voltage is greater than the capacitor voltage
the diode will conduct, and the capacitor charges rapidly (C is small)
When the capacitor voltage is greater than the input voltage, the diode is reverse-bias:
the capacitor will slowly discharge through the load

70. Diode: Clamping circuit
During negative half-cycle, Diode is ‘ON’
The capacitor charges up to
During positive half-cycle, Diode is ‘OFF’

71. Diode: Clamping circuit
During positive half-cycle, Diode is ‘OFF’
The capacitor charges up to
No charging. Instead, discharging occurs up to

72. Diode: Clamping circuit
During positive half-cycle, Diode is ‘OFF’
The capacitor charges up to
No charging. Instead, discharging occurs up to

73. Diode: Clamping circuit
During positive half-cycle, Diode is ‘OFF’
The capacitor charges up to
No charging. Instead, discharging occurs up to

74. Diode: Clamping circuit
During positive half-cycle, Diode is ‘OFF’
The capacitor charges up to
No charging.
Instead, discharging occurs
up to

75. Diode: Clamping circuit
During negative half-cycle, Diode is ‘ON’
The capacitor charges up to
During positive half-cycle, Diode is ‘OFF’

76. Diode: Digital logic (Low) (Low) (High) (Low) (Low) (High) (High)

77. Diode: Digital logic (Low) (Low) (High) (Low) (Low) (High) (High)

78. Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (High)

79. Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (High)

80. Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)

81. Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)

82. Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)