Question

A transformer operating at primary voltage 8 kV and secondary voltage 160 V serves a load of 80 kW. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be:

Options

• 800 Ω and 1.06 Ω 

• 10 Ω and 500 Ω 

• 800 Ω and 0.32 Ω 

• 1.06 Ω and 500 Ω

Answer 1

800 Ω and 0.32 Ω 

Explanation:

`((8xx10^3)^2)/"R"_"P"` = 80 × 10³   `[∵ "P" = "V"^2/"R"]`

⇒ R_P = 800  Ω

Similarly, `(160)^2/"R"_"S"` = 80 × 10³

⇒ R_S = 0.32 Ω