Question

Rating (in kVA) equation when using a single-phase transformer as an autotransformer.

A. Rating = (Primary voltage x Secondary voltage) / (Primary current).
B. Rating = (Primary voltage x Secondary current) / (Primary current).
C. Rating = (Primary current x Secondary voltage) / (Primary voltage).
D. Rating = (Primary current x Secondary current) / (Primary voltage).

Answer 1

The rating equation for using a single-phase transformer as an autotransformer is: Rating = (Primary voltage x Secondary voltage) / (Primary current).

Step-by-step explanation:

The rating equation for using a single-phase transformer as an autotransformer is:

Rating = (Primary voltage x Secondary voltage) / (Primary current).

The equation shows that the rating of the transformer is determined by the product of the primary voltage and the secondary voltage, divided by the primary current.

For example, if the primary voltage is 100V, the secondary voltage is 50V, and the primary current is 5A, the rating would be:

Rating = (100V x 50V) / 5A = 1000VA or 1kVA.