1
GATE ECE 2009
+2
-0.6
The switch in the circuit shown was on position ‘a’ for a long time and is moved to position ‘b’ at time t = 0. The current i(t) for t > 0 is given by A
0.2e-125t u(t) mA
B
20e-1250t u(t) mA
C
0.2e-1250t u(t) mA
D
20e-1000t u(t) mA
2
GATE ECE 2008
+2
-0.6
The following series RLC circuit with zero initial conditions is excited by a unit impulse function $$\delta$$(t). For t > 0, the output voltage Vc(t) is
A
$$\frac2{\sqrt3}\left(e^{-\frac{\displaystyle1}{\displaystyle2}t}-e^{-\frac{\displaystyle\sqrt3}{\displaystyle2}t}\right)$$
B
$$\frac2{\sqrt3}te^{-\frac12t}$$
C
$$\frac2{\sqrt3}e^{-\frac12t}\cos\left(\frac{\sqrt3}2t\right)$$
D
$$\frac2{\sqrt3}e^{-\frac12t}\sin\left(\frac{\sqrt3}2t\right)$$
3
GATE ECE 2008
+2
-0.6
The following series RLC circuit with zero initial conditions is excited by a unit impulse function $$\delta$$(t). For t > 0, the voltage across the resistor is
A
$$\frac1{\sqrt3}\left(e^{-\frac{\displaystyle\sqrt3}{\displaystyle2}t}-\;e^{-\frac12t}\right)$$
B
$$e^{-\frac12t}\left[\cos\left(\frac{\sqrt3}2t\right)\;-\;\frac1{\sqrt3}\sin\left(\frac{\sqrt3}2t\right)\right]$$
C
$$\frac2{\sqrt3}e^{-\frac{\displaystyle1}{\displaystyle2}t}\sin\left(\frac{\sqrt{3t}}2\right)$$
D
$$\frac2{\sqrt3}e^{-\frac{\displaystyle1}{\displaystyle2}t}\cos\left(\frac{\sqrt{3t}}2\right)$$
4
GATE ECE 2008
+2
-0.6

The circuit shown in the figure is used to charge the capacitor C alternately from two current sources as indicated. The switches S1 and S2 are mechanically coupled and connected as follows Assume that the capacitor has zero initial charge. Given that u(t) is a unit step function, the voltage Vc(t) across the capacitor is given by

A B C D GATE ECE Subjects
Network Theory
Control Systems
Electronic Devices and VLSI
Analog Circuits
Digital Circuits
Microprocessors
Signals and Systems
Communications
Electromagnetics
General Aptitude
Engineering Mathematics
EXAM MAP
Joint Entrance Examination