1
GATE ECE 1998
MCQ (Single Correct Answer)
+1
-0.3
If $$F\left(s\right)\;=\;\frac\omega{s^2\;+\;\omega^2}$$, then the value of $$\underset{t\rightarrow\infty}{\lim\;}f\left(t\right),\;\left\{where\;F\left(s\right)\;is\;the\;L\left[f\left(t\right)\right]\right\}$$
A
cannot be determined
B
is zero
C
is unity
D
is infinite
2
GATE ECE 1998
MCQ (Single Correct Answer)
+1
-0.3
Consider a unity feedback control system with open-loop transfer function $$G\left(s\right)\;=\;\frac K{s\left(s\;+\;1\right)}$$ . The steady state error of the system due to a unit step input is
A
zero
B
K
C
1/K
D
infinite
3
GATE ECE 1998
MCQ (Single Correct Answer)
+1
-0.3
The Nyquist plot of a loop transfer function G$$(j\omega )$$ H$$(j\omega )$$, of a system encloses the (-1, j0) point. The gain margin of the system is
A
less than zero
B
zero
C
greater than zero
D
infinity
4
GATE ECE 1998
MCQ (Single Correct Answer)
+1
-0.3
The transfer function of a phase lead controller is $${\textstyle{{1 + 3Ts} \over {1 + Ts}}}.$$ The maximum value of phase provided by this controller is
A
$$90^\circ $$
B
$$60^\circ $$
C
$$45^\circ $$
D
$$30^\circ $$