Q.1
Which of these is not true for a class B amplifier?
  • a) It has zero DC bias
  • b) They have an efficiency less than that of class A amplifiers
  • c) The quiescent power dissipation is zero
  • d) The conduction angle is only 180°
Q.2
What is the output of a class B amplifier for sinusoidal input?
  • a) Sinusoidal amplifier
  • b) Half-sinusoidal
  • c) Sinusoidal with higher frequency
  • d) Square wave
Q.3
How do we obtain sinusoidal output out of a class B amplifier?
  • a) By using non-sinusoidal inputs
  • b) By utilizing two transistors
  • c) By biasing it in the active region
  • d) By adding a capacitor to the output
Q.4
In a class B amplifier, it is found that DC power is 25W, find the ac power.
  • a) 10 W
  • b) 62.5 W
  • c) 25 W
  • d) 50 W
Q.5
When is the maximum efficiency of class B amplifier achieved?
  • a) When VMAX = VCC
  • b) When two transistors are used
  • c) When VMIN = 0
  • d) Efficiency is always constant
Q.6
What is the disadvantage of a class B push-pull amplifier?
  • a) The efficiency reduces
  • b) The figure of merit increases
  • c) The cross-over distortion occurs
  • d) The Q-power dissipation is very large
Q.7
Read statements and select the correct option below.
  • a) A and B are both correct and B is the correct reason for A
  • b) A is correct and B is incorrect
  • c) Both A and B are correct but B is not the correct reason for A
  • d) Both A and B are incorrect
Q.8
Why does no DC current flow in the primary winding of the output transformer of class B push-pull amplifier?
  • a) Because DC currents from both transistors flow in opposite directions
  • b) Because the net impedance is very high to allow flow of current
  • c) The winding only allows AC current to flow
  • d) Current only flows in secondary winding due to the presence of load at that side
Q.9
Which of these is incorrect for complementary symmetry push-pull amplifiers?
  • a) During positive cycle NPN transistor conducts
  • b) It is easier to fabricate on IC
  • c) Size of the transformer required reduces
  • d) Efficiency and figure of merit are same as transformer coupled push-pull amplifier
0 h : 0 m : 1 s