Question

Which transformer ratio is required for neon signs to operate from a 130 V line supplying 12 kV?

a) 1:100
b) 1:12
c) 100:1
d) 12:1

Answer 1

The transformer ratio required for neon signs to operate from a 130 V line supplying 12 kV is approximately 92.31, but the closest standard transformer ratio is 100:1.

Step-by-step explanation:

The transformer ratio required for neon signs to operate from a 130 V line supplying 12 kV is determined by the ratio of the output voltage to the input voltage. Since the transformer is stepping up the voltage from 130 V to 12 kV, the ratio would be the output voltage divided by the input voltage.

To calculate the transformer ratio, we use the formula: Transformer Ratio = Secondary Turns / Primary Turns. Given that we need to step up the voltage from 130 V to 12,000 V (or 12 kV), the transformer ratio can be calculated as follows: Transformer Ratio = 12,000 V / 130 V = 92.31. However, since transformer ratios are typically given as whole numbers, the closest standard transformer ratio that can be commonly found and that would exceed the minimum requirement is 100:1.

Therefore, the correct choice would be a transformer with a 100:1 ratio to properly step up the voltage from 130 V to 12 kV which is necessary for the operation of neon signs.