# Find the maximum AC current flowing through the generator.

• driedupfish

#### driedupfish

QUESTION 10***
A generator with output voltage ε(t) = εmax cos (ωt) is connected to the primary of a transformer. A resistor is connected to the transformer secondary. The transformer has an iron core with N1 turns on the primary and N2 turns on the secondary. Assume that the transformer is ideal and dissipates no energy.

Find the maximum AC current flowing through the generator.

http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys212/oldexams/exam3/fa07/fig10b.gif [Broken]

http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys212/oldexams/exam3/fa07/fig10a.gif [Broken]

V2 = (N2 / N1) V1. <--- equation for transformer

V2 is the voltage across the second coil, and V1 is the generator voltage, which is Emax.
So to solve for the max AC current, I divide V2 by R, which would yield choice A, but the answer is B, can someone explain what I did wrong?

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They have asked Imax in primary circuit.
V2 = (N2 / N1) V1.
Next input power = outputpower.
So V2 I2 = V1I1
I1 = (V2/V1)I2.. Substitute the values of V2/V1 and I2 to get the result.