GATE EE 2015 Question Paper (07-Feb-2015) (Shift 2)

A buck converter feeding a variable resistive load is shown in the figure. The switching frequency of the switch S is $100kHz$ and the duty ratio is 0.6. The output voltage $V_0$ is $36V$. Assume that all the components are ideal, and that the output voltage is ripple-free. The value of $R$ (in Ohm) that will make the inductor current ($i_L$) just continuous is _________.

For the switching converter shown in the following figure, assume steady-state operation. Also assume that the component are ideal, the inductor current is always positive and continuous and switching period is $T_S$. If the voltage $V_L$ is as shown, the duty cycle of the switch $S$ is ________.

In the given rectifier, the delay angle of the thyristor $T_1$${}_{\text{­}}$ measured from the positive going zero crossing of $V_s$ is $30^{\circ }$. If the input voltage $V_s$ is $100sin\left(100\pi t\right)V$, the average voltage across $R$ (in volt) under steady-state is_______.

For the linear time invariant systems that are Bounded Input Bounded stable, which one of the following statement is TRUE?

The z – transform of a sequence $x\left[n\right]$ is given as $X\left(z\right)=2z+4-4/z+3/z^2$. if y[n] is the first difference of $x\left[n\right]$, then $Y\left(z\right)$ is given by