What can cause an increase in voltage drop during transmission?

An increase in voltage drop during transmission occurs when the resistance of the conductor is higher. Decreased conductor size directly contributes to this because as the cross-sectional area of a conductor decreases, its resistance increases. When the resistance increases, it causes a larger percentage of the total voltage to be dropped across the conductor when current flows through it. This means that the voltage available at the load will be reduced, resulting in a higher voltage drop.

In the context of the other choices, short-circuiting typically reduces the overall impedance in the circuit, potentially minimizing voltage drop temporarily in affected areas. Improved insulation does not affect the electrical resistance of the conductors themselves, and using surge protectors primarily addresses voltage spikes but does not influence the continuous voltage drop experienced during regular transmission.