What type of transformer decreases the voltage from primary to secondary coil?

A step-down transformer is specifically designed to decrease the voltage from the primary coil to the secondary coil. It accomplishes this by using a primary coil with more turns of wire than the secondary coil. According to the principles of electromagnetic induction, when alternating current flows through the primary coil, it generates a magnetic field that induces a current in the secondary coil. The voltage output in the secondary coil is inversely related to the number of turns of wire in the coils. Therefore, with fewer turns in the secondary than in the primary, the voltage is reduced.

This operational principle is crucial in applications where lower voltages are needed for various electrical devices, ensuring they function safely and efficiently without being exposed to higher input voltages. Other types of transformers have different functions: a step-up transformer increases voltage, an auto transformer adjusts voltage without isolation, and an isolation transformer provides the same voltage on both sides while ensuring electrical isolation.