Transformer questions - primary, secondary, gaaaah

[sutekilady]

Transformer questions - primary, secondary, gaaaah!

Hello, I really need help with this. Much appreciated! Thank you so much in advance for any help!

Homework Statement

A step-up transformer has exactly 100 turns in the primary and exactly 200 turns in the secondary. If the voltage in the primary is 100 V ± 2 %, what is the voltage in the secondary?

a. 200 V ± 4 V
b. 200 V ± 4 %
c. none of the other answers
d. 100 V ± 4 %
e. 200 V ± 2 V

Homework Equations

Vs/Vp=Ns/Np

The Attempt at a Solution

OK now here, I know the voltage should be 200V. But the uncertainty ... ? I really don't know where to even begin with that. I chose answer b. 200 V ± 4 %, and it was wrong.

 

[sutekilady]

Thank you!

 

[xcvxcvvc]

There is no more uncertainty introduced in the secondary voltage, so it is still +/- 2%. To trick you, they omitted this selection and instead put the real value of 2% which is just 2% of 200 (4 volts)