Input and output voltages of a transformer?

1. Apr 26, 2004

derfrok

okay, I Don't quite grasp this concept but!. Vo/Vi = No/Ni.

And I have this problem. A Generator at a power plant produces AC at 24,000 V.A transformer steps this up to 345,000 V for transmission over power lines. IF there are 2000 turns of wire in the input coil of the transformer, how many turns must there be in the output coil?

2. Apr 26, 2004

sridhar_n

Heres how u do the problem....

First let me tell u the basics of a transformer. A transformer is a mutual inductance based device that transfers power from one part to the other. It does so by virtue of stepping up the voltage or the current.
i.e VI = constant. So if the input voltage, current and the number of turns are V1, I1 and N1 and those on the o/p are V2, I2 and N2, then,

N1*V1*I1 = N2*V2*I2 .

So, the voltage or current level can be stepped up or stepped down accordingly. Do u understand the concept now????

And about the solution to ur problem, I think u have answered ur qn. The answer is: Vin/Vout = Nin/Nout.

Sridhar

3. Apr 26, 2004

HallsofIvy

Staff Emeritus
Yes, "Vo/Vi = No/Ni" . Also you are told that Vi= 24000, Vo= 345000 and Ni= 2000. Put those into the equation and you have:

345000/24000= No/2000. Can you solve for No?

4. Apr 27, 2004

derfrok

ah! thanks guys.. see i thought i had the answer down! But, the tutors at my school we're telling me something else! Thanks for ellaborating!