Which of the following is true about a step-down transformer?

A step-down transformer is designed to reduce the voltage from the primary winding to the secondary winding while simultaneously increasing the current. This is a fundamental characteristic of transformers governed by the principle of conservation of energy, which states that the power input to the transformer (voltage multiplied by current in the primary winding) must equal the power output (voltage multiplied by current in the secondary winding), minus losses.

In a step-down transformer, because the voltage is decreased, the number of turns in the secondary winding is fewer than in the primary winding. According to the transformer equation, as the voltage decreases, the current must increase to maintain the energy balance. Therefore, in a step-down transformer, the function is to decrease the voltage while increasing the current proportionally.

This principle is important in various applications where lower voltage and higher current are necessary, such as in power distribution systems for efficient energy transfer to residential and commercial users. This makes the understanding of step-down transformers critical for anyone working in electrical engineering or related fields.