1
GATE ECE 2017 Set 1
+1
-0.3
For the operational amplifier circuit shown, the output saturation voltages are $$\pm \,\,15V$$. The upper and lower threshold voltages for the circuit are, respectively.
A
+5 V and -5V
B
+7 V and -3V
C
+3V and -7V
D
+3V and -3V
2
GATE ECE 2016 Set 1
+1
-0.3
Consider the constant current source shown in the figure below. Let $$\beta$$ represent the current gain of the transistor

The load current I0 through RL is

A
$${I_0} = \left[ {{{\beta + 1} \over \beta }} \right]{{{V_{ref}}} \over R}$$
B
$${I_0} = \left[ {{\beta \over {\beta + 1}}} \right]{{{V_{ref}}} \over R}$$
C
$${I_0} = \left[ {{{\beta + 1} \over \beta }} \right]{{{V_{ref}}} \over {2R}}$$
D
$${I_0} = \left[ {{\beta \over {\beta + 1}}} \right]{{{V_{ref}}} \over {2R}}$$
3
GATE ECE 2016 Set 1
Numerical
+1
-0
The following signal Vi of peak voltage 8V is applied to the non-inverting terminal of an ideal Opamp. The transistor has VBE = 0.7 V, $$\beta \, = \,100;$$ VLED = 1.5 V, VCC = 10V and -VCC = -10V.

The number of times the LED glows is ______.

4
GATE ECE 2015 Set 3
Numerical
+1
-0
In the circuit shown using am ideal opamp, the 3-dB cut-off frequency (in Hz) is _____.