In the voltage reference circuit shown in the figure, the op-amp is ideal and the transistors Q₁, Q₂,….., Q₃₂ are identical in all respects and have infinitely large values of common – emitter current gain $$\beta $$. The collector current (I_C) of the transistors is related to their base emitter voltage (V_BE) by the relation I_C = I_S exp (V_BE/V_T); where I_s is the saturation current. Assume that the voltage V_P shown in the figure is 0.7 V and the thermal voltage V_T=26mV

The output voltage V_out (in volts) is _____.

The amplifier circuit shown in the figure is implemented using a compensated operational amplifier (op-amp), and has an open-loop voltage gain, A₀ 10⁵ V/V and an open-loop cut-off frequency, f_C = 8 Hz. The voltage gain of the amplifier at 15 kHz, in V/V, is __________.

A p-i-n photo diode of responsivity 0.8A/W is connected to the inverting input of an ideal opamp as shown in the figure, +V_CC = 15V, - V_CC = -15V, Load resistor R_L = 10 k$$\Omega $$ . If 10$$\mu $$W of power is incident on the photodiode, then the value of the photocurrent (in $$\mu $$A) through the load is _____.

An ideal opamp has voltage source V₁, V₃, V₅, ......, V_N-1, connected to the non- inverting input and V₂, V₄, V₆, .....V_N connected to the inverting input as shown in the figure below (+V_CC= 15 volt, -V_CC = -15 volt). The voltage V₁, V₂, V₃,V₄, V₅, V₆ ....... are 1, -1/2, 1/3, -1/4, 1/5, -1/6, .... volt, respectively. As N approaches infinity, the output voltage (in volt) is _______