A synchronous generator is rated at 40 MVA, 10 kV and 50 Hz. The base impedance of the generator will be:

Question

Question

This question was previously asked in

HPCL Engineer Electrical 01 Nov 2022 Official Paper

Answer 1

The correct answer is option 4):(2.5 Ω)

Concept:

For an AC network,

VA Rating = \(V^2\over Z\)

Where V is voltage in volt

Z is the impedance (base) in Ω

Calculation:

VA rating = 40 MVA = 40 × 10⁶ VA

V = 10 × 10³ volts

= \(\frac{(10\times 10^3)^2}{40\times 10^6}= \frac{10^2}{40}= 2.5 \ \Omega\)