# A sample power system network is shown in the given figure. The reactances marked are in p.u. The p.u. value of Y22 of the Bus Admittance Matrix (YBus ) is

1.  j 10.0

2.  j 0.4

3.  -j 0.1

4.  - j 20.0

4

j 10.0

Explanation :
No Explanation available for this question

# Transmission line has a total series reactance of 0.2 p.u. Reactive power compensation is applied, at the midpoint of the line and it is controlled such that midpoint voltage of the transmission line is always maintained at 0.98 pu. If voltage at both ends of the line are maintanined at 1.0 pu, then steady state power transfer limit of the transmission line is

1.  9.8 pu

2.  4.9 pu

3.  19.6 pu

4.  5 pu

4

5 pu

Explanation :
No Explanation available for this question

# A 3-phase transformer has rating of 20MVA, 220 kV (star) + 33 kV (delta) with leakage reactance of 12 %. The transformer reactance (in ohms referred to each phase of the L.V. delta-connected side is

1.  23.5

2.  19.6

3.  18.5

4.  8.7

4

19.6

Explanation :
No Explanation available for this question

# If a 75 MVA, 10 kV synchronous generator has Xd = 0.4 p.u, then Xd value (in p.u.) to a base of 100 MVA, 11 kV is

1.  5.78

2.  0.279

3.  0.412

4.  0.44

4

0.44

Explanation :
No Explanation available for this question

# The inertia constant H of a machine of 200 MVA is 2 p.u. Its value corresponding to 400 MVA will be

1.  4.0

2.  2.0

3.  1.0

4.  0.5

4

1.0

Explanation :
No Explanation available for this question

# A 3 - induction motor takes 100 kW at 415 V, 50 Hz and a power factor of 0.80 lagging. What is the kVAr rating of a capacitor bank to improved the power factor to 0.9 lagging, if the capacitor bank is connected to delta?

1.  6.25

2.  7.99

3.  7.91

4.  8.82

4

8.82

Explanation :
No Explanation available for this question

# A 3 - Φ induction motor takes 120 kW at 415 V 50 Hz and a power factor of 0.8 lagging. What is the capacitance per phase, if its power factor is improve to 0.9 and capacitor bank is connected in star

1.  587 F

2.  440 F

3.  560 F

4.  600 F

4

587 F

Explanation :
No Explanation available for this question

# A 220 V, 8 kW, 50 Hz, 1- motor working at full load with an efficiency of 85% has a power factor of 0.8 lagging. If a capacitor is connected across the motor terminals to raise the overall power factor to unity, then current through the capacitor will be

1.  33.5 amps

2.  32.0 amps

3.  30 amps

4.  41 amps

4

32.0 amps

Explanation :
No Explanation available for this question

# In a 4 bus system, the circuit breakers and the various zones of the protection are shown in the given figure. If the circuit breakers E, F and G trip, the location of the fault is on

1.  Bus 2

2.  Bus 1

3.  Bus 3

4.  Bus 4

4

Bus 2

Explanation :
No Explanation available for this question

# Consider the problem of relay co-ordination .for the distance relays R1 and R2 on, adjacent lines of a transmission system (see figure); The Zone 1 and Zone. 2 'Settings. for both the relays are indicated on the diagram. Which of the following indicates the-correct time setting, for the Zone 2 of the relays R1 and R2

1.  TZ2Ro=0.6 s,TZ2R2=0.3 s

2.  TZ2Ro=0.3 s,TZ2R2=0.6 s

3.  TZ2Ro=0.3 s, TZ2R2=0.3 s

4.  TZ2Ro=0.1 s, TZ2R2=0.3 s

4