What is the primary voltage and amperage if the secondary voltage of a transformer is 24 volts and 20 amps with a turns ratio of 5:1?

To determine the primary voltage and amperage of a transformer based on the provided secondary specifications and turns ratio, it's essential to apply the transformer equations related to voltage and current.

Given the secondary voltage is 24 volts and the secondary current is 20 amps with a turns ratio of 5:1, you can find the primary voltage using the relationship dictated by the turns ratio. The turns ratio indicates that for every 5 turns in the primary winding, there is 1 turn in the secondary winding. This means that the primary voltage is 5 times the secondary voltage. Thus, you calculate the primary voltage as follows:

Primary Voltage = Secondary Voltage × Turns Ratio

Primary Voltage = 24 volts × 5 = 120 volts.

Next, to find the primary current, you can use the fact that power (measured in watts) must remain constant in an ideal transformer. The relationship can be expressed as:

Power (primary) = Power (secondary)

Primary Voltage × Primary Current = Secondary Voltage × Secondary Current.

From this, we can rearrange to find the primary current:

Primary Current = (Secondary Voltage × Secondary Current) / Primary Voltage

Primary Current = (24 volts × 20 amps) / 120 volts = 4