Question

A neon sign that requires a voltage of 11,000 v is plugged into a 120-v wall outlet. what turns ratio (secondary/primary) must a transformer have to power the sign?

Answer 1

The equation that relates the voltages and the number of turns in a transformer is

`(V_s)/(V_p)= (N_s)/(N_p)`
where
`V_s = 120 V` is the voltage in the secondary coil,
`V_p=11000 V` is the voltage in the primary coil, and
`N_s` and
`N_p` are the number of turns on the secondary and primary coils.

Using the numbers, we find the ratio between the number of turns:

`(N_s)/(N_p)= (V_s)/(V_p)= (120 V)/(11000 V)=0.0109`