Electrical Engineering: Power Electronics MCQ

In the circuit shown, a 5V Zener diode is used to regulate the voltage across load R₀. The input is an unregulated DC voltage with a minimum value of 6V and a maximum value of 8V. the value of R_S is  6Ω.The Zener diode has a maximum rated power dissipation of 2.5W, Assuming the Zener diode to be ideal, the minimum value of R₀ is ____ _Ω

Consider the buck boost converter shown.Switch Q is operating at 25 kHz and 0.75 duty-cycle.Assume diode and switch to be ideal.Under steady- state condition ,the average current flowing through the inductor is___ 

The circuit shown in the figure uses matched transistors with a thermal voltage V_T = 25 mV. The base currents of the transistors are negligible. The value of the resistance R in kΩ  that is required to provide 1 μA bias current for the differential amplifier block shown is _______.

The input voltage V DC of the buck-boost converter shown below varies from 32 V to 72 V. Assume that all components are ideal, inductor current is continuous, and output voltage is ripple free. The range of duty ratio D of the converter for which the magnitude of the steady-state output voltage remains constant at 48 V is

The figure below shows an uncontrolled diode bridge rectifier supplied from a 220 V, 50 Hz, 1- phase ac source. The load draws a constant I0 = 14 A. The conduction angle of the diode D1 in degrees (rounded off to two decimal places) is _________.