Secondary voltage and current?

[SAT2400]

Secondary voltage and current??

Homework Statement

A load resistor is placed across the secondary terminals of a step-down transformer with a turn ratio of 4:1. If the primary voltage and current are 120V and 1A., What will be the secondary voltage and current? Assume 100% efficiency.

Homework Equations

Ns/Np = Vs/Vp = Ip/Is

The Attempt at a Solution

Ns should be 4,,right??
but If Ns = 4..then, I don't get the right answer...
why is Np 4?? Np is primary isn't it??

The answers were 30v and 4A.

 

[tiny-tim]

A load resistor is placed across the secondary terminals of a step-down transformer with a turn ratio of 4:1. If the primary voltage and current are 120V and 1A., What will be the secondary voltage and current? Assume 100% efficiency.
…
Ns should be 4,,right??
but If Ns = 4..then, I don't get the right answer...
why is Np 4?? Np is primary isn't it??

The answers were 30v and 4A.

Hi SAT2400!

It's a step-down transformer, and you're told the ratio is 4:1, so Ns/Np = 1/4.