Physical electronics devices and ics miscellaneous

Physical electronics devices and ics miscellaneous

Easy Questions

Physical Electronics Devices and ICs

Physical electronics devices and ics miscellaneous
  1. The common emitter amplifier shown in the figure below is biased using a 1 mA ideal current source. The approximate base current value is—










  1. View Hint View Answer Discuss in Forum

    The given figure

    IB ≈
    IC
    		≈
    1 mA
    		≈ 10 µA
    β100

    Correct Option: B

    The given figure

    IB ≈
    IC
    		≈
    1 mA
    		≈ 10 µA
    β100

  1. The transconductance gm of the transistor shown below in figure is 10 mS. The value of the input resistance Rin is–










  1. View Hint View Answer Discuss in Forum

    The given figure

    Given, gm = 10 mS

    We know that Rin =
    hfe
    		=
    β

    gmgm

    =
    50
    		= 5 kΩ
    10 mS

    Correct Option: C

    The given figure

    Given, gm = 10 mS

    We know that Rin =
    hfe
    		=
    β

    gmgm

    =
    50
    		= 5 kΩ
    10 mS

  1. The perfectly matched silicon transistors are connected as shown in figure below. The value of current I will be—










  1. View Hint View Answer Discuss in Forum

    The given circuit

    Given, β = 1000 for each transistor, VBE = 0·7 V, and both the transistors are perfectly matched.
    From figure I ≈ current flowing through 1 kΩ resistance.
    Applying KVL to the 1 kΩ resistance loop, we get
    – 1 kΩ. I – VBE + 5 = 0

    or I =
    4·3V
    		= 4·3 mA
    1 kΩ

    Hence alternative (C) is the correct choice.

    Correct Option: C

    The given circuit

    Given, β = 1000 for each transistor, VBE = 0·7 V, and both the transistors are perfectly matched.
    From figure I ≈ current flowing through 1 kΩ resistance.
    Applying KVL to the 1 kΩ resistance loop, we get
    – 1 kΩ. I – VBE + 5 = 0

    or I =
    4·3V
    		= 4·3 mA
    1 kΩ

    Hence alternative (C) is the correct choice.

  1. In a normally biased npn transistor, the electrons in the emitter have enough energy to overcome the barrier potential of the—








  1. View Hint View Answer Discuss in Forum

    In a normally biased npn transistor, the electrons in the emitter have enough energy to over come, the barrier potential of the base-emitter junction.

    Correct Option: A

    In a normally biased npn transistor, the electrons in the emitter have enough energy to over come, the barrier potential of the base-emitter junction.

  1. When a free electron recombines with a hole in the base region, the free electron becomes—








  1. View Hint View Answer Discuss in Forum

    When a free electron recombines with a hole in the base region, the free electron becomes a valence electron.

    Correct Option: B

    When a free electron recombines with a hole in the base region, the free electron becomes a valence electron.