# How to find source current in transformer

1. Jul 15, 2011

1. The problem statement, all variables and given/known data

Refer to the figure attached. The single phase "exact"-equivalent circuit of a practical transformer has the following equivalent circuit parameters: Np/Ns = 2400V/240V, Rp = 14.1, Xp = 31.2, Rs = 78.5*10^(-3), Xs = 120.5*10^(-3), Rc = 156*10^3, Xm = 172*10^3. The load is a resistor with a value of RL = 1.95. The source voltage is 2400 with an angle of 30 degrees.

Determine the source current I1.
Determine the voltage Ep.

2. The attempt at a solution

I calculated the equivalent impedance to be 216.683+j32.6405 ohms.
And I assume that I1 would just be the source voltage 2400 ang(30) divide by the equivalent impedance.. but I keep getting the wrong answer

#### Attached Files:

• ###### Capture.JPG
File size:
17.5 KB
Views:
81
2. Jul 15, 2011

### The Electrician

I assume the reason you think your answer is wrong is because your text has the answer.

If you will show the answer you get and also the "correct" answer, we should be able to determine your problem.