CONTROL SYSTEM MCQS SET 34

CONTROL SYSTEM MCQS SET 34

1. For the transfer function
G(s) H(s) = 1 / s(s+1) (s+0.5), the phase cross-over frequency is
a) 0.5 rad/sec         b) 0.707 rad/sec          c) 1.732 rad/sec
d) 2 rad/sec
Answer: b

2. The gain margin (in dB) of a system having the loop transfer function
G(s) H(s) = 2 / s(s+1) is
a) 0             b) 3            c) 6               d) 8
Answer: d

3. The gain margin for the system with open loop transfer function
G(s) H(s) = G(s) =2(1+s) / s2 is
a) 8                b) 0         c) 1                d) -8
Answer: 0

4. Statement 1: In constant M circles, as M increases from 1 to 8 radius of circle increases from 0 to 8 and Centre shifts from (-1,0) to (-8,0)
Statement 2: The circle intersects real axis at point (-1/2, 0)
a) Statement 1 is TRUE, 2 is FALSE
b) Statement 1 is FALSE, 2 is TRUE
c) Statement 1 & 2 TRUE
d) Statement 1 & 2 FALSE
Answer: d

5. Assertion (A): Relative stability of the system reduces due to the presence of transportation lag.
Reason (R): Transportation lag can be conveniently handled by Bode plot.
a) Both A and R are true but R is correct explanation of A
b) Both A and R are true but R is correct explanation of A
c) A is true but R is false
d) A is false but R is true
Answer: b

6. Assertion (A): The phase angle plot in Bode diagram is not affected by the variation in the gain of the system.
Reason(R): The variation in the gain of the system has no effect on the phase margin of the system.
a) Both A and R are true but R is correct explanation of A
b) Both A and R are true but R is correct explanation of A
c) A is true but R is false
d) A is false but R is true
Answer: c

7. A system has poles at 0.01 Hz, 1 Hz and 80Hz, zeroes at 5Hz, 100Hz and 200Hz. The approximate phase of the system response at 20 Hz is:
a) -90°                 b) 0°               c) 90°             d) -180°
Answer: a

8. The constant M-circle represented by the equation x^2+2.25x+y^2=-1.25 has the value of M equal to:
a) 1            b) 2           c) 3             d) 4
Answer: c

9. What is the value of M for the constant M circle represented by the equation 8x^2+18x+8y^2+9=0?
a) 0.5              b) 2                c) 3         d) 8
Answer: c

10. The constant N loci represented by the equation x^2+x+y^2=0 is for the value of phase angle equal to:
a) -45°             b) 0°             c) 45°              d) 90°
Answer: d