The number of turns on the primary coil of a step-down transformer is:

• A the same as the number of secondary turns
• B more than the number of secondary turns
• C less than the number of secondary turns
• D zero

This transformer is designed to reduce the voltage from 240 V to 9 V.

The primary current is 0.15 A.

State the equation linking primary voltage, primary current, secondary voltage, and secondary current for a transformer.

Calculate the secondary current, assuming that the transformer is 100% efficient.

A user notices that the power adapter becomes warm when it is working. Suggest how this will affect the power output of the transformer compared to its power input.