The figure shows a half-wave rectifier with a 475 µF filter capacitor. The load draws a constant current I₀= 1 A from the rectifier. The figure also shows the input voltage V_i , the output voltage V_C and the peak-to-peak voltage ripple on V_C.The input voltage V_i is a triangle-wave with an amplitude of 10 V and a period of 1 ms.

The value of the ripple u (in volts) is ______________.

Resistor R₁ in the circuit below has been adjusted so that I₁ = 1 mA. The bipolar transistor Q1 and Q2 are perfectly matched and have very high current gain, so their base currents are negligible. The supply voltage V_cc is 6 V. The thermal voltage kT/q is 26 mV.

The value of R₂ (in $$\Omega $$ ) for which I₂ = 100 $$\mu {\rm A}$$ is ________.

Which one of the following statements is correct about an ac-coupled common- emitter amplifier operating in the mid-band region?

In the opamp circuit shown, the Zener diodes Z1 and Z2 clamp the output voltage V_o to +5 V or -5 V. The switch S is intially closed and is opened at time t = 0

The time t = t_{1 (in seconds) at which Vo changes state is _____.}