1 out of 5 attempt he three phase system of a town distribut

1 out of 5 attempt he three phase system of a town distributes power with a line voltage of 16.8 kV rms. A pole transformer connected to single wire and ground steps down the high-voltage wire to 140 V rms and serves a house as shown in figure. Round your final answers to four decimal places. The three-phase system of a town distributes power with a line 16.8 kV rms 140 V rms

Solution

Here,

Primary side:

line voltage = 16.8 kv (rms)

Phase voltage = line voltage / 1.732.

= 16800 / 1.732

= 9699.4 volts ( rms)

On secondary side:

phase voltage = 140 volts (rms)

Turns ratio = ( primary voltage / secondary voltage)

= 9699.48 / 140

= 69.28

Turns ratio = 70 turns approximately