Transformers

Which of the following are the same for both primary and secondary windings in a transformer?

The regulation of a transformer is least affected by changes in frequency at which loading?

What is the reason why transformers are rated in kVA instead of kW?

What is the reason why the kVA rating of an ordinary two-winding transformer is increased when connected as an autotransformer?

At what load is the efficiency of a transformer be zero?

When a V-V bank is converted to a Δ-Δ bank, what is the percentage increase in its capacity?

Which one is the main cause of the noise in transformer?

At what loading condition is the efficiency of a power transformer maximum?

How does the voltage per turn in the primary windings related to the voltage per turn in the secondary windings?

The eddy current loss in a transformer are reduced by laminating the core, the laminations being insulated from each other by which of the following?

Which of the following transformer connections of a transformer will give the highest secondary voltage?

Which one is true about an autotransformer?

Which of the following is true in a distribution transformer?

What is the purpose of putting the transformer windings under oil?

Which of the following is true about a transformer?

Which one dictates the primary current in a CT?

The no load input power of a transformer is practically equal to which of the following?

What principle is used in transformer?

What is the purpose of connecting sometimes a “reactor” in series to a transformer?

In the transformer equivalent circuit, the core loss is represented by which of the following circuit elements?