Question 1
The equivalent of the block diagram in the figure is given as

(GATE 2004 || EC || MCQ||2 MARK)




Question 2
Despite the presence of negative feedback, control systems still have problems of instability because the
(GATE 2005 || EC || MCQ ||1 MARK)
Components used have nonlinearities
Dynamic equations of the systems are not known exactly
Mathematical analysis involves approximations
System has large negative phase angle at high frequencies
Question 3
Negative feedback in a closed-loop control system does not
( GATE 2015 || EC || MCQ ||1 MARK)
reduce the overall gain
reduce bandwidth
improve disturbance rejection
reduce sensitivity to parameter variation
Question 4
The transfer function Y(s)/R(s) of the system shown is

(GATE 2010 || EC || MCQ ||1 MARK)
0
[Tex]\frac{1}{s + 1}[/Tex]
[Tex]\frac{2}{s + 1}[/Tex]
[Tex]\frac{2}{s + 3}[/Tex]
Question 5
For the following system,

When X1(s) = 0, the transfer function is: Y(s) / X2(s)
(GATE 2014 || EC || MCQ ||1 MARK)
(s + 1) / s2
1 / (s + 1)
(s + 2) / [s(s + 1)]
(s + 1) / [s(s + 2)]
Question 6
By performing cascading and/or summing differencing operations using transfer function block [Tex]G_1(s)[/Tex] and [Tex]G_2(s)[/Tex], one CANNOT realize a transfer function of the form
(GATE 2015 || EC || MCQ ||2 MARK)
[Tex]G_1(s)G_2(s)[/Tex]
[Tex]\frac{G_1(s)}{G_2(s)}[/Tex]
[Tex]G_1(s) \left( \frac{1}{G_1(s)} + G_2(s) \right)[/Tex]
[Tex]G_1(s) \left( \frac{1}{G_1(s)} - G_2(s) \right)[/Tex]
Question 7
The block diagram of a feedback control system is shown in the figure. The overall closed-loop gain G of the system is

(GATE 2016 || EC || MCQ ||1 MARK)
G = G1G2 / (1 + G1H1)
G = G1G2 / (1 + G1G2 + G1H1)
G = G1G2 / (1 + G1G2H1)
G = G1G2 / (1 + G1G2 + G1G2H1)
Question 8

(| GATE 2019 || EC || MCQ ||2 MARK)
[Tex]H(s) = \frac{s^2 + 1}{2s^2 + 1}[/Tex]
[Tex]H(s) = \frac{s^2 + 1}{s^3 + 2s^2 + s + 1}[/Tex]
[Tex]H(s) = \frac{s + 1}{s^2 + s + 1}[/Tex]
[Tex]\frac{Y(s)}{X_2(s)} = \frac{\frac{1}{s}}{1 + \frac{1}{s} \cdot \frac{s}{s+1}} = \frac{s+1}{s(s+2)}[/Tex]
Question 9
The block diagram of a feedback control system is shown in the figure.

The transfer function Y(x)/ X(s) of the system is
(G1 + G2) / (1 + G1H)
(G1 + G2 + G1G2H) / (1 + G1H)
G1(s)[1 / G1(s) + G2(s)]
G1(s)[1 / G1(s) + G2(s)]
Question 10

(GATE 2003 || EC || MCQ ||2 MARK)
[Tex]\frac{6}{s^2 + 29s + 6}[/Tex]
[Tex]\frac{6s}{s^2 + 29s + 6}[/Tex]
[Tex]\frac{s(s+2)}{s^{2} + 29s + 6}[/Tex]
[Tex]\frac{s(s+27)}{s^{2} + 29s + 6}[/Tex]
There are 169 questions to complete.