If the primary coil of a transformer has more turns than the secondary, what type of transformer is it?

When the primary coil of a transformer has more turns than the secondary coil, it is known as a step-down transformer. This type of transformer reduces the voltage from the primary to the secondary side, allowing for a lower voltage to be delivered to the load.

In a step-down transformer, the relationship between the number of coils and the voltage is based on the principle of electromagnetic induction. According to this principle, if the primary coil has more turns, this indicates that it operates at a higher voltage, while the secondary coil, having fewer turns, will produce a lower voltage. This functionality is fundamental for applications where a lower voltage is required for devices to operate safely and effectively.

A step-up transformer, by contrast, has more turns in the secondary coil than the primary, resulting in an increase in voltage. Variables transformers can adjust the output voltage as needed, and fixed transformers maintain a constant output voltage. However, these options do not apply to the situation described in the question.