# An electromechanical closed-loop control system has-the following characteristic equation: s3 + 6Ks2 + (K + 2) s + 8 = 0 where K is the forward gain of the system. The condition for closed loop stability is

1.  K = 0.528

2.  K=2

3.  K=0

4.  K =-2.58

4

K = 0.528

Explanation :
No Explanation available for this question

# What is the charging kVAr taken by a 10 km length of the cable when connected to an 11 kV, 50 Hz supply The capacitance measured between any two cores of a three phase belted cable is 0.5 F/km.

1.  380 kVAr

2.  150 kVAr

3.  114 kVAr

4.  400 kVAr

4

380 kVAr

Explanation :
No Explanation available for this question

# None of the poles of a linear control system in the right half of s-plane. For a bounded input, the output of this system

1.  is always bounded

2.  could be unbounded

3.  always tends to zero

4.  none of these

4

could be unbounded

Explanation :
No Explanation available for this question

# The capacitance of a 3 core lead sheathed cable measured between any two of the conductors with ; sheath earthed is 0.19 F per kin: The kvA required to keep 16 kms of the cable charged when:: connected to 20 kV, 50 Hz supply will be

1.  720 kVA

2.  780 kVA

3.  763 kVA

4.  600 kVA

4

763 kVA

Explanation :
No Explanation available for this question

# Which of the following function is the transfer of a system having the Nyquist plot in the figure

1.  K/s(s + 2)2(s + 5)

2.  K/ s2 (s + 2)(s + 5)

3.  K(s +1)/s2 (S + 2)(s + 5)

4.  K(s + 1)(s + 3)/s2(s + 2)(s + 5)

4

K/ s2 (s + 2)(s + 5)

Explanation :
No Explanation available for this question

# If the sheath resistance is 2.14Ω/k.na and that of the conductor is 0.1625Ω/km, and mutual inductance of the shealth is 3.13 x 10-7H/m. When the cable is 2 km long and supply is 50 Hz, the ratio of sheath loss to core loss of the cable will be

1.  0.35

2.  0.277

3.  0.0277

4.  0.0354

4

0.0277

Explanation :
No Explanation available for this question

# The system with the open loop transfer function G(s) H(s)= 1/ s(s2 + s + 1) has a gain margin of

1.  -6dB

2.  0 dB

3.  3.5 dB

4.  6 dB

4

0 dB

Explanation :
No Explanation available for this question

# The feedback control system shown in the figure is stable

1.  for all K > 0

2.  Only if K > 1

3.  only if 0

4.  only if 0

4

only if 0 < K<1

Explanation :
No Explanation available for this question

# The dielectric has a relative permittivity of 2.4 and a loss angle of 0.031 radian for 2.5 km length of cable 120. The dielectric loss will be

1.  968 Watt

2.  945 Watt

3.  750 Watt

4.  none of these

4

968 Watt

Explanation :
No Explanation available for this question

1.  K < -1

2.   -1 < K < 1

3.  1 < K < 3

4.  K > 3

4