The figure below shows an uncontrolled diode bridge rectifier supplied form a $$220$$ Z$$V,$$ $$50$$ $$Hz,$$ $$1$$-phase $$ac$$ source. The load draws a constant $${{\rm I}_0}$$ $$=14A.$$ The conduction angle of the diode $${D_1}$$ in degrees (rounded off to two decimal places) is ______________.

For the power semiconductor devices $$IGBT, MOSFET,$$ Diode and Thyristor, which one of the following statements is TRUE?

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

A $$3$$-phase voltage source inverter is supplied from a $$600V$$ $$DC$$ source as shown in the figure below. For a star connected resistive load of $$20\,\,\Omega $$per phase, the load power for $${120^ \circ }$$ device conduction, in $$kW,$$ is ___________.