1

GATE ECE 2001

Subjective

+5

-0

The circuit shown in Fig. is operating in steady-state with switch $${S_1}$$ closed. The switch $${S_1}$$ is opened at $$t\, = \,0$$.

(a) Find $${i_L}\left( {{0^ + }} \right)$$.

(b) Find $${e_1}\left( {{0^ + }} \right)$$.

(c) Using nodal equations and Laplace transform approach, find an expression
for the voltage across the capacitor for all $$t\, = \,0$$.

2

GATE ECE 2000

Subjective

+5

-0

The network $$N$$ in Fig. consists only of two elements: a resistor of $$1\Omega $$ and an inductor of L Henry. $$A$$ $$5$$ $$V$$ source is connected at the input at $$t\, = \,0$$ seconds. The inductor current is zero at $$t\, = \,0$$. The output voltage is found to be $$5{e^{ - 3t}}\,\,V,$$ for $$t\, = \,0$$.

(a) Find the voltage transfer function of the network.

(b) Find L, and draw the configuration of the network.

(c) Find the impulse response of the network.

3

GATE ECE 1999

Subjective

+5

-0

In the circuit of figure, the switch $$'S'$$ has remained open for a long time. The switch closes instantaneously at $$ t = 0$$.
n

(a) Find $${V_0}$$ for $$t \le 0$$ and as $$t \to \infty $$.

(b) Write an expression for $${V_0}$$ as a function of time for $$0 \le t \le \infty $$.

(c) Evaluate $${V_0}$$ at $$t = 25\,\,\mu $$sec.

4

GATE ECE 1994

Subjective

+5

-0

The circuit shown in the figure, is initially in its steady state. Switch is opened at
t = 0.

(1) Determine the initial voltage, V

(2) Calculate the voltage, V

(1) Determine the initial voltage, V

_{C}(0^{-}), across the capacitor, and the initial current, i_{L}(0^{-}) , through the indicator.(2) Calculate the voltage, V

_{L}(t) , across the inductance for t > 0.Questions Asked from Transient Response (Marks 5)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Fourier Transform Continuous Time Signal Laplace Transform Discrete Time Signal Fourier Series Fourier Transform Discrete Fourier Transform and Fast Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Discrete Time Linear Time Invariant Systems Transmission of Signal Through Continuous Time LTI Systems Sampling Transmission of Signal Through Discrete Time Lti Systems Miscellaneous

Network Theory

Control Systems

Digital Circuits

General Aptitude

Electronic Devices and VLSI

Analog Circuits

Engineering Mathematics

Microprocessors

Communications

Electromagnetics