Transistor Audio Power Amplifiers(Electrical Engineering Questions ) Questions and Answers

Question 1. If the gain versus frequency curve of a transistor amplifier is not flat, then there is distortion ?
  1.    Amplitude
  2.    Intermodulation
  3.    Frequency
  4.    None of the above
Explanation:-
Answer: Option C. -> Frequency
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 2. The driver stage usually employs_________________?
  1.    Class A power amplifier
  2.    Push-pull amplifier
  3.    Class C amplifier
  4.    None of the above
Explanation:-
Answer: Option A. -> Class A power amplifier
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 3. The pulsating d.c. applied to power amplifier causes________________?
  1.    Burning of transistor
  2.    Hum in the circuit
  3.    Excessive forward voltage
  4.    None of the above
Explanation:-
Answer: Option B. -> Hum in the circuit
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 4. The output signal voltage and current of a power amplifier are 5V and 200 mA; the values being r.m.s. What is the power output ?
  1.    1 W
  2.    2 W
  3.    4 W
  4.    None of the above
Explanation:-
Answer: Option A. -> 1 W
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 5. The push-pull circuit must use ______________ operation?
  1.    Class A
  2.    Class C
  3.    Class B
  4.    Class AB
Explanation:-
Answer: Option C. -> Class B
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 6. If the power rating of a transistor is 1W and collector current is 100mA, then maximum allowable collector voltage is________________?
  1.    1V
  2.    100V
  3.    20V
  4.    10V
Explanation:-
Answer: Option D. -> 10V
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 7. The output transformer used in a power amplifier is a _____________ transformer?
  1.    1:1 ratio
  2.    Step-up
  3.    Step-down
  4.    None of the above
Explanation:-
Answer: Option C. -> Step-down
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 8. What will be the collector efficiency of a power amplifier having zero signal power dissipation of 5 watts and a.c. power output of 2 watts ?
  1.    20%
  2.    80%
  3.    40%
  4.    50%
Explanation:-
Answer: Option C. -> 40%
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 9. What turn ratio (Np/Ns) of transformer is required to match 4 O speaker to a transistor having an output impedance of 8000 O ?
  1.    2
  2.    7
  3.    3
  4.    None of the above
Explanation:-
Answer: Option B. -> 7
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
Question 10. For the same a.c. power output as above, what should be the minimum power rating of transistor for class B operation?
  1.    10 W
  2.    4 W
  3.    8 W
  4.    None of the above
Explanation:-
Answer: Option B. -> 4 W
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!
© Lakshya_Education.com, All Right Reserved.
Contact Us services