What is the use of a surge protector?

A surge protector is designed to prevent voltage spikes from damaging electrical equipment. Voltage spikes, which can occur due to various reasons such as lightning strikes or fluctuations in the power grid, can cause significant harm to sensitive electronics. Surge protectors achieve this by diverting excess voltage away from the devices connected to them, effectively acting as a buffer and safeguarding the fragile internal components of devices.

The other options relate to functions that surge protectors do not perform. For instance, increasing voltage for high-power devices or stabilizing electrical current is not within the job description of a surge protector. Additionally, measuring electrical resistance pertains to a completely different concept in electric circuits and is typically performed using devices like multimeters. Thus, the primary role of a surge protector is to defend against harmful voltage spikes, making option B the accurate choice.