Transformers - Engineering

Q1:

When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is

A 12 V

B 120 V

C 240 V

D 2,400 V

ANS:C - 240 V

Turns ratio :a=V2/V1.
then 20=V2/12,
V2=20*12=240,
So, V2=240v.