1
GATE ECE 2016 Set 2
Numerical
+2
-0
In the opamp circuit shown, the Zener diodes Z1 and Z2 clamp the output voltage Vo to +5 V or -5 V. The switch S is intially closed and is opened at time t = 0

The time t = t1 (in seconds) at which Vo changes state is _____.

2
GATE ECE 2016 Set 2
Numerical
+2
-0
An opamp has a finite open loop voltage gain of 100. Its input offset voltage Vios (= +5mV) is modeled as shown in the circuit below. The amplifier is ideal in all other respects. Vinput is 25 mV.

The output voltage (in millivolts) is ________.

3
GATE ECE 2016 Set 1
Numerical
+2
-0
An ideal opamp has voltage source V1, V3, V5, ......, VN-1, connected to the non- inverting input and V2, V4, V6, .....VN connected to the inverting input as shown in the figure below (+VCC= 15 volt, -VCC = -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 _______
4
GATE ECE 2016 Set 1
Numerical
+2
-0
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, +VCC = 15V, - VCC = -15V, Load resistor RL = 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 _____.