____________ in a conductor causes electrical energy to be converted into heat.

• A. Voltage
• B. Amperage
• C. Resistance
• D. Power

Answer: (C)

Heat in a conductor comes from electrical energy being dissipated as the moving electrons collide with the atoms in the material. The key factor that causes this energy conversion is resistance—the opposition to current flow. As current passes through resistance, energy is transferred from the electrons to the lattice, warming the material. The rate of heat generation, or power, is described by P = I^2 R (also P = V I = V^2 / R), showing that higher current or greater resistance increases heating. In short, resistance is what turns electrical energy into heat inside the conductor, with voltage driving the current and the power formulas linking these quantities to the heat produced.