53.

For the given block diagram representation of a system, evaluate C(s)/R(s):
(A) GG, +G,)/1+G,G,G,H) ೧ ೮೮/1೬೮೫)
(© (GG, +G,)/+ GH) 0) [G,G,/1+G,H)]+G,

54. A unity feedback temperature control system has open loop transfer function
10000

G(s) = —_——_—————. If the setpoint temperature is 500 degrees Celsius, what is
(1 + 5) (1 + 0.55) (1 + 0.025)
the steady state temperature in degrees Celsius?
(A) 499.02 (B) 499.26
(C) 499.58 (D) 499.92

55. The critical gain and _ critical frequency for the characteristic equation
s‘ +22s*+10s* +s+K =O are given by :

(^) K=0.45, 0=0.212 rad/s (8)

(0 &< 0.2, ७८ 0.45 ‏8ھ‎ (0)

56. Fora type 1 system, the intersection of initial slope of Bode plot with 0 dB axis gives :
(A) Steady state error ൯) Static error constant
(C) Phase margin (D) Gain crossover frequency

57. Which of the following statements about compensators is correct?
@ Due to phase lag characteristic of lag compensators, it cannot be used to improve phase
margin.
(ii) The pole and zero of lag compensator must be located substantially lower than gain
crossover frequency of the compensated system.

൩) The main effect of lag compensator is to attenuate the high frequency magnitude
response without adding additional negative phase shift at these frequencies.

(iv) The zero of lag compensator is chosen one decade below the gain crossover frequency of
compensated system

(^) (0), Gi), (iii) are correct ൯) 0, ii), (iv) are correct
(C) (0), (1), (iv) are correct (0) ൭, ൬, (11), (iv) are correct

A 13 080/2023
[P.T.0.]