I am attaching the missing figure
If we assume 100% efficiency, this means that the input power of the transformer must be equal to the output power
We divide output/input
240,000/12,000 = 20
This means that the transformer has a turns ratio of 1:20
ns/np = 20/1 = 20
The voltage is amplified 20 times by the transformer, but this also means that the current decreases by a factor of 20, so the total power remains the same.
