A non inverting op - amp amplifier is shown in figure. The o/p voltage is

Let the magnitude of the gain in the inverting op - amp amplifier circuit shown be $$x$$ with switch $${S_1}$$ open. When the switch $${S_1}$$ is closed, the magnitude of gain becomes.

In the transistor amplifier shown in figure, the ratio of small signal voltage gain when the emitter resistor is bypassed by the capacitor $$'{C_e}'$$ to when it is not bypassed. (Assuming of simplified approximate $$h$$- parameter model for transistor) is

The unit - impulse response of a unity - feedback control system is given by $$c\left( t \right) = - t{e^{ - t}} + 2\,\,{e^{ - t}},\,\left( {t \ge 0} \right)$$ the open loop transfer function is equal to