Electrical Engg (EEE) - MCQ Practice Questions

In a three-phase bridge rectifier, if the input AC voltage is 400V (line), what is the approximate average DC output voltage?

Which of the following devices has the highest switching frequency capability among modern power semiconductors?

In a boost converter operating in continuous conduction mode (CCM) with duty cycle D=0.6, input voltage 24V, and output voltage 60V, what is the efficiency if losses are 5%?

A PWM inverter produces an output frequency of 50Hz with a carrier frequency of 10kHz. What is the modulation index if the peak modulating signal is 0.8V and the peak carrier signal is 1V?

In a half-bridge inverter, what is the minimum dead time required to prevent shoot-through if the switching frequency is 20kHz?

Which protection method is MOST suitable for protecting a thyristor against voltage transients in industrial applications?

A current-controlled PWM rectifier maintains unity power factor. If the input current harmonic distortion THD is 3%, what is the approximate displacement power factor?

In a soft-switching zero-voltage switching (ZVS) converter, the main advantage is:

A MOSFET with on-state resistance RDS(on)=0.5Ω carries an average current of 50A at 100kHz. What is the approximate conduction loss?

Which topology is preferred for high-power renewable energy inverters (>100kW) in 2024-25 grid applications?

In a synchronous buck converter, if the duty cycle is 0.7 and the switching frequency is 500kHz, what is the approximate inductor ripple current (ΔIL) with input voltage 48V and output voltage 24V?

A diode-clamped five-level inverter reduces the voltage stress on individual switches compared to a two-level inverter by a factor of:

A single-phase AC voltage controller with a resistive load has a firing angle of 45°. What is the RMS output voltage as a fraction of input RMS voltage?

Which semiconductor device combination is used in a cycloconverter to convert AC-to-AC with frequency reduction?

In a matrix converter (direct AC-to-AC), how many bi-directional switches are required for three-phase input and three-phase output?

A resonant DC-link inverter operates at 200kHz. The resonant frequency must be:

For an industrial induction motor variable frequency drive (VFD) using vector control, what is the typical output frequency range in 2024-25 applications?

A three-phase PWM rectifier with active front-end reduces grid distortion to THD < 5%. This is primarily achieved by:

In isolated DC-DC converters for EV fast-charging stations, which topology provides the best isolation and efficiency above 1kW?

In a boost converter operating in continuous conduction mode (CCM), if the input voltage is 24V, output voltage is 48V, and switching frequency is 100kHz, what is the duty cycle of the converter?