Correct option is C
The efficiency of two identical transformers under load conditions can be determined by performing a back-to-back test.
In this test, the two transformers are connected in parallel, and the primary windings of both transformers are connected to the same source.
The secondary windings are then connected to a load.
The efficiency of two identical transformers under load conditions can be measured and compared using a method known as the back-to-back test, also referred to as the Sumpner's test.
This method is particularly effective because it allows the assessment of the transformer efficiency under load conditions without the necessity to supply the full load power from the external circuit, thus saving energy and reducing the requirements for high power sources for testing.
Advantages:
Energy-efficient, as most of the load power is circulated internally.
Reduced requirements for a high-capacity power source for testing under full-load conditions.
Allows assessment of efficiency under simulated full-load conditions without the need for actual full-power dissipation.
Limitations:
It mainly provides information on steady-state efficiency and losses, without insights into transient behaviors or other dynamic characteristics.
Accurate for similar types of transformers but might not fully replicate all operational conditions.
