What hazard can result from overloading a circuit or using damaged insulation?

• A. Potential electric shock to a person
• B. The fuses will automatically reset
• C. The circuit will naturally store energy
• D. Overheating and possible fire

Answer: (D)

When a circuit is overloaded or insulation is damaged, more current flows through the wires than they can safely carry. The extra current heats the conductor (I^2R heating), and this heat can cause the insulation to break down or melt. If insulation is compromised, heat and possible arcing can ignite surrounding materials, making overheating and fire the primary hazard. Fuses don’t automatically reset; they blow to interrupt the circuit and must be replaced. Circuits don’t inherently store useful energy in normal operation, so energy storage isn’t the hazard here. The overheating and fire risk best explains the danger in this scenario.