Hello friends;
In a book there is a following question.

A two-phase generator is connected to two 90 load resistors. Each coil generates 120 V ac. A common neutral line exists. How much current flows through the common neutral line?

The answers are
1. 1.33 A
2. 1.88 A
3. 2.66 A
4. 1.77 A

The answer according to the book is 1.77 but i am unable to find that current? I think the correct answer is 2.66 A.

Please help me what is the correct answer and how?

Regards

 

Angel... because the generated voltages are 90° apart and the phase loads equal and resistive, the neutral current is the vectoral sum of both phase-currents.

Then for 90 Ohm load the phase-current is 120/90 or 1.333 A. Thus the neutral-current is SQRT (2) x 1.333 or 1.88 A.

Regards, Phil Corso
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