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  1. 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 µF/km.
    1. 380 kVAr
    2. 150 kVAr
    3. 114 kVAr
    4. 400 kVAr
Correct Option: A

Let CL be the capacitance between any two cores.

CL =
C0
2

C0 = 2 CL = 2 × 0.5 × 10 = 10µF
IC = Vp.ω.C0 =
VL
ω.2CL
3

Total charging kVAr
= √3 (VL).(LC) × 10-3
= √3 × VL ×
VL
× 2CL × 10-3
3

= 2 (VL)². ω. CL × 10-3
= 2 × (11000)² × 2π × 50 ×
10
× 10-3 × 10-6
2

= 380 kVAr.



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