The correct answer is A. temperature rise.
A transformer is a device that transfers electrical energy from one circuit to another without a change in frequency. It does this by using electromagnetic induction to create a magnetic field that induces a voltage in a second circuit.
The maximum load that a power transformer can carry is limited by its temperature rise. This is because the transformer’s insulation can only withstand a certain amount of heat before it starts to degrade. If the transformer is overloaded, the temperature of the insulation will rise and it will eventually fail.
The other options are not correct because they do not directly affect the transformer’s ability to carry a load.
- Option B, dielectric strength of oil, is the ability of an insulating material to withstand a voltage without breaking down. This is important for transformers, but it is not the factor that limits the maximum load that a transformer can carry.
- Option C, voltage ratio, is the ratio of the output voltage to the input voltage of a transformer. This is important for transformers, but it does not directly affect the transformer’s ability to carry a load.
- Option D, copper loss, is the loss of electrical energy in the transformer’s windings due to the resistance of the copper. This is a factor that affects the transformer’s efficiency, but it does not directly affect the transformer’s ability to carry a load.