
A boost converter operates at 25 kHz with a duty cycle 0.6. Input is 15 V, load is 10 \(\Omega\). Assuming ideal components, compute the equivalent input resistance \(R_{in}\) seen by the source. (Round off to 2 decimal places.) 
Consider the buck-boost converter shown. Switch Q operates at 25 kHz with a duty-cycle of 0.75. Assume diode and switch are ideal. Under steady-state, the average current flowing through the inductor is \(\underline{\hspace{1cm}}\) A. 
Given an open-loop transfer function \(GH = \frac{100}{s}(s+100)\) for a unity feedback system with a unit step input \(r(t)=u(t)\), determine the rise time \(t_r\).
Consider a linear time-invariant system represented by the state-space equation: \[ \dot{x} = \begin{bmatrix} a & b -a & 0 \end{bmatrix} x + \begin{bmatrix} 1 0 \end{bmatrix} u \] The closed-loop poles of the system are located at \(-2 \pm j3\). The value of the parameter \(b\) is: