If a transformer has an efficiency of 95%, how much power must be supplied to deliver 1 kVA to a load?

To determine how much power must be supplied to deliver 1 kVA to a load with a transformer efficiency of 95%, we start by understanding the concept of efficiency in transformers. Efficiency is defined as the ratio of the output power to the input power, expressed as a percentage.

In this case, the transformer is 95% efficient, meaning that for every 100 units of input power, 95 units are delivered as useful output power. To find the required input power to achieve 1 kVA output, we can use the efficiency formula rearranged to solve for input power:

Input Power = Output Power / Efficiency

Given that the output power required is 1 kVA (or 1 kW since kVA is often equated with kW in purely resistive loads) and the efficiency is 0.95 (which is 95% expressed as a decimal), we can perform the calculation:

Input Power = 1 kVA / 0.95

Calculating this gives:

Input Power = 1.0526 kVA, which can be rounded off to 1.053 kVA.

Thus, to deliver 1 kVA to the load, the transformer must be supplied with approximately 1.053 k