What happens to the current in the secondary coil of a transformer rated at 28 volts and a primary of 115 volts?

To understand what happens to the current in the secondary coil of a transformer when given the primary and secondary voltages, it is critical to apply the transformer formula, which relates the primary and secondary voltages (V) and currents (I) along with the number of turns in the coils. The formula is given by:

[ \frac{V_p}{V_s} = \frac{N_p}{N_s} = \frac{I_s}{I_p}

]

where:

• ( V_p ) is the primary voltage,
• ( V_s ) is the secondary voltage,
• ( N_p ) is the number of turns in the primary coil,
• ( N_s ) is the number of turns in the secondary coil,
• ( I_p ) is the primary current,
• ( I_s ) is the secondary current.

In your case, the transformer operates at a primary voltage of 115 volts and a secondary voltage of 28 volts.

A step-down transformer reduces the voltage from primary to secondary; consequently, the current in the secondary coil will increase relative to the primary current due to the conservation of power principle, assuming an ideal transformer where power input equals power output:

[ P_p