Chapter 3 Audio Power Amplifiers MCQs 15 min Score: 0 Attempted: 0/15 Subscribe 1. . An amplifier that operates in the linear region at all times is (A) Class A (B) Class B (C) Class AB (D) Class CShow All Answers 2. . A certain class A amplifier delivers 5W to a load with an input signal power of 100 mW. The power gain is (A) 100 (B) 50 (C) 250 (D) 5Show All Answers 3. . The peak current a class A power amplifier can deliver to a load depends on the (A) Maximum rating of the power supply (B) Quiescent current (C) Current in the bias resistor (D) Size of the heat sinkShow All Answers 4. . For maximum output, a class A power amplifier must maintain a value of quiescent current that is (A) One-half the peak load current (B) Twice the peak load current (C) At least as large as the peak load current (D) Just above the cutoff valueShow All Answers 5. . A certain class A power amplifier has VCEQ = 12V and ICQ = 1A. The maximum signal power output is (A) 12 W (B) 6 W (C) 1 W (D) 0.707 WShow All Answers 6. . The efficiency of a power amplifier is the ratio of the power delivered to the load to the (A) Input signal power (B) Power from the DC power supply (C) Power dissipated in last stage (D) None of the aboveShow All Answers 7. . The maximum efficiency of a class A power amplifier is (A) 25% (B) 50% (C) 79% (D) 98%Show All Answers 8. . The transistor in a class B amplifier are biased (A) In cutoff (B) In saturation (C) At midpoint of load line (D) Right at cutoffShow All Answers 9. . Crossover distortion is a problem for (A) Class A amplifiers (B) Class B amplifiers (C) Class AB amplifiers (D) Class C amplifiersShow All Answers 10. . A BJT class B push-pull amplifier with no transformer coupling uses (A) Two npn transistors (B) Complementary pair transistors (C) Two pnp transistors (D) DirectShow All Answers 11. . The maximum efficiency of a class B push-pull amplifier is (A) 25 % (B) 50 % (C) 79 % (D) 98 %Show All Answers 12. . The output of a certain two-supply class B push-pull amplifier has a VCC of 20 V. If the load resistance is 50 Ω, the value of IC(sat) is (A) 5 mA (B) 0.4 A (C) 4 mA (D) 40 mAShow All Answers 13. . The maximum efficiency of a class AB amplifier is (A) Higher than class B (B) Same as class B (C) Same as class A (D) Slightly less than class BShow All Answers 14. . The power dissipation of class C amplifier is normally (A) Less than class A (B) Less than class B (C) Less than class AB (D) Greater than classes A, B or ABShow All Answers 15. . The transistor in a class C amplifier conducts for (A) More than 180° of the input cycle (B) One-half of the input cycle (C) A very small percentage of the input cycle (D) A complete 360°Show All Answers
