A 125 km long transmission line is loaded at 110 kV. If the loss of the line in 20 MW and the load is 175 MVA the resistance of the line is

The correct answer is option 1):(7·9 Ω/phase )

Concept:

Apparent Power (S) = V × I

Where,

I = Current

V = Voltage Power loss per phase 

power loss  P_L = I² × R W

Calculation:

Given

Given

V= 110 kV

S = 175 MVA 

All the calculations are done per phase only

Now load current (I) can be calculated as I = \((175 × 10^6)\over (110 × 10^3)\) per phase

I = 1.59 × 10³ A

Now, using the power loss Formula-

P_L = I² x R

20 x 10⁶ = (  1.59 × 103 ) x R

So, R = 7.9 ohm/phase