What is the expected VA rating at 5A for a current transformer with a burden designation of B0.1 according to IEEE C57.13?

The expected VA rating for a current transformer is derived from its burden designation and the primary current level. In this case, the burden designation B0.1 corresponds to a standard burden of 0.1 ohms.

When calculating the VA rating for a current transformer at a specified primary current, you use the formula:

VA = (Current in Amperes)² × Burden in Ohms.

For a primary current of 5A and a burden of 0.1 ohms, the calculation is as follows:

VA = (5A)² × (0.1 ohms) = 25A² × 0.1 ohms = 2.5 VA.

Thus, the correct choice reflects this calculation, providing the expected VA rating for the current transformer operating under those specified conditions.