Power Electronics MCQs December 24, 2025November 19, 2024 by u930973931_answers 20 min Score: 0 Attempted: 0/20 Subscribe 1. Power electronics is primarily concerned with: (A) The generation of power (B) The conversion, control, and regulation of electrical power (C) The transmission of power (D) The storage of electrical power 2. Which of the following is NOT a typical application of power electronics? (A) Amplification of audio signals (B) Motor drives (C) Power supplies for electronic devices (D) Solar power systems 3. Which of the following is a primary function of a rectifier in power electronics? (A) To regulate voltage (B) To convert DC to AC (C) To convert AC to DC (D) To step up or step down voltage 4. What does a chopper circuit in power electronics do? (A) Converts AC to DC (B) Converts DC to AC (C) Converts a DC signal into a pulsating DC signal (D) Smooths out DC voltage 5. The efficiency of a power electronic system is defined as the ratio of: (A) Output power to input power (B) Input power to output power (C) Total power to loss power (D) Output power to input current 6. In a power electronic system, a thyristor is mainly used for: (A) Power amplification (B) Power switching (C) Frequency modulation (D) Signal filtering 7. Which of the following is the main advantage of using a PWM (Pulse Width Modulation) technique in power electronics? (A) Provides precise control over the output voltage and frequency (B) Increases switching speed (C) Reduces heat generation (D) Reduces the input power 8. What is the primary difference between a diode and a thyristor in power electronics? (A) A diode can control high power, while a thyristor is used only for low power (B) A thyristor is a purely analog device, while a diode is digital (C) A thyristor is used for signal amplification, while a diode is used for switching (D) A diode is a unidirectional device, while a thyristor can switch on and off 9. A buck converter in power electronics is used to: (A) Step up the input voltage (B) Rectify AC to DC (C) Convert DC to AC (D) Step down the input voltage 10. What is the main purpose of a voltage regulator in power electronics? (A) To convert AC to DC (B) To increase the voltage (C) To maintain a constant output voltage despite variations in input voltage or load (D) To reduce the current 11. Which of the following power semiconductor devices is commonly used in high-power applications for switching and rectification? (A) MOSFET (B) IGBT (C) BJT (D) LED 12. In a power inverter, the main function is to: (A) Convert AC to DC (B) Convert DC to AC (C) Regulate voltage (D) Control current flow 13. Which of the following is an advantage of using MOSFETs in power electronic circuits? (A) High switching speed and efficiency (B) Can handle very high voltage (C) Low efficiency at high frequencies (D) Low switching speed but high voltage handling 14. In a power electronics system, what is the primary function of a capacitor in filtering circuits? (A) To store and release energy to smooth out voltage fluctuations (B) To block high-frequency signals (C) To convert AC into DC (D) To limit the current in the circuit 15. Which of the following is an example of an AC-to-AC power conversion device? (A) Cycloconverter (B) Inverter (C) Rectifier (D) Chopper 16. The primary function of a transformer in power electronics is to: (A) Increase the frequency of the signal (B) Rectify the AC signal (C) Step up or step down voltage (D) Convert DC to AC 17. The efficiency of a power converter is affected by: (A) All of the above (B) Conduction losses (C) Magnetic losses (D) Switching losses 18. In a power electronics circuit, a heat sink is typically used to: (A) Cool down semiconductor devices and prevent overheating (B) Reduce the output power (C) Store electrical energy (D) Regulate the output voltage 19. Which of the following techniques is used for controlling the output voltage of a DC-DC converter? (A) Amplitude Modulation (AM) (B) Frequency Modulation (FM) (C) Pulse Width Modulation (PWM) (D) Pulse Amplitude Modulation (PAM) 20. The main application of power electronics in renewable energy systems is for: (A) Signal processing (B) Storing energy in batteries (C) Power conversion, such as inverters and rectifiers for solar and wind energy systems (D) Converting audio signals to electrical power