A step up transformer used in an automobile has a potential difference across the primary of 2200 V and a potential difference across the secondary of 25 V. What is the ratio of the numbers of turns of wire on the primary to the secondary?

N1/N2 = V1/V2 = 2200/25 = 88/1.

Based on the information given, this is a step-down transformer.

To find the ratio of the numbers of turns of wire on the primary (N₁) to the secondary (N₂), we can use the formula:

V₁/V₂ = N₁/N₂

Where:
V₁ = Potential difference across the primary (2200 V)
V₂ = Potential difference across the secondary (25 V)

By rearranging the formula, we can solve for the ratio:

N₁/N₂ = V₁/V₂

Substituting the given values:

N₁/N₂ = 2200/25

Calculating:

N₁/N₂ = 88

Therefore, the ratio of the number of turns of wire on the primary to the secondary is 88.