Introduction

In this scenario, a secondary transformer is being used to reduce the main supply voltage from 220V to 11V. We are given that the primary side of the transformer draws a current of 5A, while the secondary side has a current of 90A. We need to calculate the efficiency of the transformer based on these values.

Efficiency Calculation

The efficiency of a transformer is defined as the ratio of the output power to the input power. In this case, we can calculate the efficiency using the following formula:

Efficiency = (Output Power / Input Power) * 100

To calculate the output power, we need to know the voltage and current on the secondary side of the transformer. In this case, the secondary voltage is given as 11V and the secondary current is given as 90A.

Output Power = Secondary Voltage * Secondary Current

Output Power = 11V * 90A

Output Power = 990W

To calculate the input power, we need to know the voltage and current on the primary side of the transformer. In this case, the primary voltage is given as 220V and the primary current is given as 5A.

Input Power = Primary Voltage * Primary Current

Input Power = 220V * 5A

Input Power = 1100W

Now, we can substitute the values of the output power and input power into the efficiency formula to calculate the efficiency of the transformer.

Efficiency = (990W / 1100W) * 100

Efficiency = 90%

Explanation

The efficiency of a transformer represents how effectively it can convert the input power into the desired output power. In this case, the transformer is designed to step down the voltage from 220V to 11V.

When the primary side of the transformer draws a current of 5A, it converts the input power into a higher current of 90A on the secondary side, while reducing the voltage from 220V to 11V.

The efficiency of the transformer is determined by the losses that occur during the transformation process. These losses include copper losses in the windings and core losses. Copper losses occur due to the resistance of the transformer windings, while core losses occur due to hysteresis and eddy currents in the magnetic core.

In an ideal transformer, there would be no losses and the efficiency would be 100%. However, in practical transformers, some energy is lost as heat during the transformation process, resulting in a lower efficiency.

In this case, the efficiency of the transformer is calculated to be 90%. This means that 90% of the input power is successfully converted into the desired output power, while the remaining 10% is lost as heat.

Overall, the efficiency of a transformer is an important factor to consider in order to minimize energy losses and improve the overall performance of the electrical system.