Electrical Engg (EEE) - MCQ Practice Questions

Which power semiconductor device is best suited for high-frequency switching applications above 100 kHz?

In a boost converter with duty cycle D = 0.4, input voltage Vi = 48V, and output voltage Vo = 80V, what is the voltage stress across the switch?

The holding current (Ih) specification of a thyristor is important to ensure:

A single-phase half-wave rectifier with a firing angle of 45° is connected to a 230V, 50Hz AC source. Calculate the RMS output voltage.

Which of the following topologies is most suitable for soft-switching operation in modern DC-DC converters?

In an IGBT, the latching current phenomenon occurs when:

What is the purpose of a freewheeling diode in a converter circuit?

In a three-phase VSI (Voltage Source Inverter), if the modulation index (Ma) is 0.8 and DC link voltage is 400V, what is the peak phase voltage?

Which PWM technique provides the lowest THD in the output voltage of an inverter?

In a step-down DC-DC converter (buck), the inductor current ripple is ΔI = 2A at 100 kHz switching frequency. If D = 0.5 and Vi = 24V, what is the approximate inductance value?

What does the snubber circuit in a power converter primarily protect against?

In a controlled rectifier circuit, the commutation overlap angle (μ) depends on:

Which cooling method is most effective for high-power semiconductor modules operating above 5 kW?

In a full-bridge DC-DC converter, when both upper switches conduct simultaneously, what occurs?

The power factor of a thyristor-based rectifier with firing angle 60° is approximately:

In a current-source inverter (CSI), the DC link component is typically:

Which parameter determines the minimum OFF-time in a PWM converter?

For an AC voltage controller with RMS output voltage of 230V from a 230V, 50Hz source at 30° firing angle, what is the power factor?

In modern 2024-25 EV charging systems, what is the typical efficiency target for on-board DC-DC converters?

A thyristor has a forward breakover voltage of 800V and a holding current of 200mA. What is the minimum gate current required to trigger the device if the gate sensitivity is 40mA/V?