How do step-up transformers affect voltage and amperage?

Step-up transformers are designed to increase the voltage in an electrical circuit. The principle governing their operation is based on electromagnetic induction and the law of conservation of energy. When a step-up transformer is used, the primary coil (input side) has fewer turns of wire compared to the secondary coil (output side). This design allows the transformer to boost the input voltage to a higher output voltage.

As the voltage is increased, the transformer must also adhere to the conservation of power, which states that the power in the primary coil must equal the power in the secondary coil (ignoring losses). Power is calculated as the product of voltage and current (P = V × I). Therefore, when the voltage is increased, amperage (current) must decrease proportionally to keep the total power of the circuit constant.

For instance, if you were to double the voltage in a step-up transformer, the current would be halved, assuming no losses. This is why the correct response indicates that step-up transformers increase voltage while decreasing amperage. It’s important to note that the actual current in the circuit will depend on the load connected to the transformer.

Thus, the correct answer accurately reflects the function of step-up transformers in electrical systems.