# A50 Hz alternator is rated 500MVA, 20 kV, With Xd =1.0 per Unit and Xd"= 0.2 per unit. It supplies a purely resistive load of 400 MW at 20 kV. The load is connected directly across the generator terminals when a symmetrical fault occurs at the load terminals The initial rms current in the generator in per unit is

1.  7.22

2.  0.4

3.  3.22

4.   2.2

4

3.22

Explanation :
No Explanation available for this question

# If the excitation Of the synchronous generator fails, it acts as a

1.  synchronous motor

2.  synchronous generator

3.  induction motor

4.  induction generator

4

induction generator

Explanation :
No Explanation available for this question

# Which of the following is the response of a spring-mass-damper with under-damping

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# A linear time-invariant system initially at rest, when subjected to a unit-step input, gives a response yt?=te-t, t>0. The transfer function of the system is

1.  1/(s+1)2

2.  1/s(s+1)2

3.  s/(s+1)2

4.  1/s+1

4

s/(s+1)2

Explanation :
No Explanation available for this question

# The positive,, negative and zero sequence impedance of a solidly grounded System under steady state condition always follow the relation

1.  Z1>Z2>Z0

2.  Z1

3.  Z0 < Z1 < Z2

4.   none of these

4

Z1>Z2>Z0

Explanation :
No Explanation available for this question

# For what positive value of K does polynomial s4+8s3+24s2+32s+K have roots with zero real parts

1.  10

2.  20

3.  40

4.  80

4

80

Explanation :
No Explanation available for this question

# The characteristic equation of a control system is given as s4+4s3+4s2+3s+K=0 what is the value of K for which this system is marginally stable

1.  9/16

2.  19/16

3.  29/16

4.  39/16

4

39/16

Explanation :
No Explanation available for this question

# The positive sequence current for a L-L fault of a 2 kV system is 1400 A, and corresponding current for a L-L-G fault. is 2220 A. The zero sequence impedance of the System

1.  62.75Ω

2.  4.5275Ω

3.  5.275Ω

4.  0.5275Ω

4

0.5275Ω

Explanation :
No Explanation available for this question

# The transfer function of a controller is given as Kp+Kd.s+Ki/s where Kp,Kd and Ki are constants. What type of controller is this

1.  Proportional

2.  Proportional plus derivative

3.  Proportional plus integral

4.  Proportional plus integral plus derivative

4

Proportional plus integral plus derivative

Explanation :
No Explanation available for this question

# The gain-phase plot of a linear control system is shown in the figure below: What are the gain-margin(GM) and the phase margin(PM) of the system

1.  GM>0 db and PM>0 degree

2.  GM>0db and PM

3.  GM0 degree

4.  GM

4