In the circuit shown below, the op-amp is ideal and Zener voltage of the diode is $\text{2.5 volts}$.

At the input, unit step voltage is applied, i.e. $v_{IN}\left ( t \right )=u\left ( t \right )$ $\text{volts}$. Also, at $\text{t = 0}$, the

voltage across each of the capacitors is zero.

The time $\text{t}$, in milliseconds, at which the output voltage $v_{OUT}$ crosses $\text{-10 V}$ is

1. $2.5$
2. $5$
3. $7.5$
4. $10$
in Others
edited