A step-down transformer is used in a laptop adapter to convert main supply voltage to a lower voltage suitable for the device.
Compare the number of turns on the primary coil of a step-down transformer with the number of turns on its secondary coil.
This transformer is designed to reduce the voltage from 240 V to 12 V. The secondary current is 2.5 A.
State the equation linking primary voltage, primary current, secondary voltage, and secondary current for a transformer.
Calculate the primary current in the transformer, assuming the transformer is 100% efficient.
A student notices that the adapter block becomes warm when the laptop is charging.
Suggest how this affects the electricity input to the transformer, assuming the secondary voltage and secondary current do not change.
