ABYC Marine Electrical Practice Exam

What happens to the electrical energy when resistance increases in a circuit?

1. It increases efficiency

2. It is transformed into heat

3. It reduces power consumption

4. It has no effect

The correct answer is: It is transformed into heat

When resistance in a circuit increases, the electrical energy is transformed into heat due to the properties of resistive materials. This phenomenon is based on Joule's Law, which states that the power loss (in the form of heat) in a resistive element is proportional to the square of the current flowing through it and the resistance (P = I²R). As the resistance increases while the current remains constant, more electrical energy is converted into thermal energy. This transformation occurs because the electrons encounter more opposition to their flow, resulting in increased collisions with the atomic structure of the material, which generates heat. In practical terms, this means that in circuits with higher resistance, there will be more heat produced for a given amount of current. Therefore, understanding this heat generation is critical for ensuring proper thermal management in marine electrical systems to prevent overheating and potential failures.