CAMRT Radiography Practice Exam

What effect do step down transformers have on voltage and amperage?

1. Decrease voltage and increase amperage

2. Decrease amperage and increase voltage

3. Maintain voltage while changing amperage

4. Increase both voltage and amperage

The correct answer is: Decrease voltage and increase amperage

Step-down transformers are specifically designed to decrease voltage while increasing amperage. This is based on the principle of conservation of energy, where the power input to the transformer (voltage times current) is nearly equal to the power output. In a step-down transformer, the number of turns of wire in the primary coil is greater than in the secondary coil. As a result, the voltage in the secondary coil is lower compared to the primary coil, which leads to a proportional increase in current or amperage in the secondary side. This means that while the voltage is reduced, the ability to carry more current is increased, making it particularly useful in applications where lower voltage is needed but higher current capacity is required. Choosing other options would reflect a misunderstanding of transformer functionality. For example, a step-up transformer, in contrast, would increase voltage and decrease current, but that's not the case here.