Q. In the circuit shown below, the op-amp is ideal and Zener voltage of the diode is 2.5 volts. At the input, unit step voltage is applied, i.e. 𝑣𝐼𝑁(𝑡) = 𝑢(𝑡) volts. . Also, at 𝑡 = 0, the voltage across each of the capacitors is zero.
The time 𝑡, in milliseconds, at which the output voltage 𝑣𝑂𝑈𝑇 crosses −10 V is
(A) 2.5 (B) 5 (C) 7.5 (D) 10