What describes voltage loss in an electrical circuit?

• A. The current flowing through the load.
• B. The drop in voltage from source to load due to conductor resistance and current.
• C. The rate of energy loss in insulation.
• D. The increase in voltage due to transformer steps up.

Answer: (B)

Voltage drop is the reduction in voltage that occurs as power travels from the source to the load through conductors. As current flows, the conductor’s resistance causes some of the voltage to be used up, so the voltage at the load end is lower than the source. The amount of drop follows Ohm’s law: V_drop equals the current times the conductor’s resistance (V = I × R). Thus, longer runs, thinner wires, or higher loads all increase the drop and can leave the load underpowered. This concept isn’t about the current itself, which is just the flow of electrons; nor is it about energy lost in insulation, which is a separate heat loss issue. And it’s certainly not about a voltage increase from a transformer, which would raise voltage rather than describe loss.