Which of the following does NOT contribute to voltage drop in a low voltage system?

The correct answer focuses on the role that transformer capacity plays in a low voltage system and its relationship to voltage drop. Voltage drop is influenced by the resistance in the conductors, which is affected by the cable’s length, total wattage load, and conductor diameter.

Transformer capacity refers to the maximum amount of load the transformer can handle and does not directly affect the amount of voltage drop across the wire. In a low voltage system, voltage drop occurs primarily due to the resistance of the conductor over a certain length of wire (longer wires can have more voltage drop) and the total current being drawn (which relates to the wattage of all the lighting elements). Additionally, the diameter of the conductors affects resistance—thinner wires have higher resistance and therefore experience greater voltage drop.

Since transformer capacity does not influence the resistance of the wire or the load drawn by the system, it does not contribute to voltage drop in a low voltage system.