What is the effect of a complete short in the secondary of a transformer?

When a complete short occurs in the secondary of a transformer, it essentially means that there is a direct connection across the secondary winding, creating a path of almost zero resistance for current to flow. This results in a situation where the secondary voltage is significantly reduced or eliminated entirely.

In a transformer, the voltage induced in the secondary winding is proportional to the number of turns in the secondary compared to the primary, according to the transformer's turns ratio. When there is a short circuit in the secondary, the impedance becomes very low, leading to a very high current flow, which can cause the voltage to drop to near zero.

Thus, the effect of such a short circuit is to eliminate the secondary voltage, as all the voltage drops across the low-resistance short rather than generating a useful output voltage. Additionally, this can potentially lead to overheating and damage in the transformer if protective measures are not in place.

Understanding this concept is crucial for recognizing how transformers operate under fault conditions and the importance of protective devices in preventing damage caused by shorts.