Problem 91-2    Source:  Problem developed by the site author.

If in the previous problem a 100 ohm load was connected to the secondary, what would be the currents in the primary and secondary? What would be the power dissipated in the load? Compare this result with the power supplied by the network to the transformer.

Solution of the Problem 91-2

Applying a load of 100 ohms to the secondary, the current flowing through the secondary will be:

Therefore, the power dissipated by the load will be:

The current in the primary can be calculated using the transformation ratio. In this case, it is known that a = V₁ / V₂ = 2. Then:

Thus, the power that the transformer absorbs from the network is:

As can be seen, in an ideal transformer, the power that the transformer absorbs from the network is exactly equal to the power supplied to the load, that is,   P₁ = P₂.