The number and direction of encirclements around the point −1 + j0 in the complex plane by the Nyquist plot of G(s) =$${{1 - s} \over {4 + 2s}}$$ is

A closed-loop control system is stable if the Nyquist plot of the corresponding open-loop transfer function

The popular plot of the transfer function G(s)=$${{10\left( {s + 1} \right)} \over {\left( {s + 10} \right)}}$$ for $$0 \le \omega < \infty $$ will be in the

Consider the Bode plot shown in the figure. Assume that all the poles and zeroes are real-valued. The value of f_H - f_L (in Hz) is ______.