Analog electronics circuits miscellaneous

Analog electronics circuits miscellaneous

Easy Questions

Analog Electronic Circuits

Analog electronics circuits miscellaneous
  1. A class-A transformer coupled, transistor power amplifier is required to deliver a power output of 10 watts. The maximum power rating of the transistor should be less than:








  1. View Hint View Answer Discuss in Forum

    Given Po (ac) = 10 Watts, PD (max) =?
    efficiency of transformer coupled amplifier = 50%

    so, η = 50% =
    Po(ac)
    Pi(dc)

    .5 =
    Po(ac)
    PD(max) + Po(ac)

    .5 PD (max) = .5 Po (ac)
    or PD (max) = Po (ac) = 10 watts.
    This is the required maximum rating of the transistor.

    Correct Option: B

    Given Po (ac) = 10 Watts, PD (max) =?
    efficiency of transformer coupled amplifier = 50%

    so, η = 50% =
    Po(ac)
    Pi(dc)

    .5 =
    Po(ac)
    PD(max) + Po(ac)

    .5 PD (max) = .5 Po (ac)
    or PD (max) = Po (ac) = 10 watts.
    This is the required maximum rating of the transistor.

  1. In the circuit shown, Ri is given by:










  1. View Hint View Answer Discuss in Forum

    From figure
    V1 = I1 R1 + (I1 + k I1) R2
    or V1 = I1 R1 + I1 R2 + I1 k R2
    or V1 = I1 (R1 + R2 + k R2)

    or
    V1
    		= R1 + R2 (1 + K)
    I1

    or Ri =
    V1
    		= R1 + R2 (1 + k)
    I1


    Correct Option: D

    From figure
    V1 = I1 R1 + (I1 + k I1) R2
    or V1 = I1 R1 + I1 R2 + I1 k R2
    or V1 = I1 (R1 + R2 + k R2)

    or
    V1
    		= R1 + R2 (1 + K)
    I1

    or Ri =
    V1
    		= R1 + R2 (1 + k)
    I1