Question

Why put foil on a doorknob when alone?

a) To prevent static electricity buildup
b) To deter microbial contamination
c) To serve as an emergency tool
d) To conduct energy more efficiently

Answer 1

Using foil on a doorknob isn't a standard practice for preventing static electricity, microbial contamination, or any other reason suggested. In clinical settings, surfaces might be coated with antimicrobial substances to prevent contamination, but foil isn't used for this purpose. Static electricity causes sparks but is generally not harmful due to the short duration of the charge transfer.

Step-by-step explanation:

There are a few reasons one might put foil on a doorknob, particularly related to electricity and conductivity. However, the idea of putting foil on a doorknob when alone is not a standard practice for any of the reasons mentioned in the question. In general, static electricity can cause a spark when touching a doorknob, especially in a low-humidity environment. This spark can be alarming or unpleasant but is usually harmless because its duration is very short, thus limiting the amount of energy transferred. Coating a doorknob with metallic foil might help distribute static charges more evenly, potentially reducing the likelihood of a shock, though this is not a common technique.

In contrast, in a clinical setting, doorknobs and other surfaces might be coated with antimicrobial substances to prevent microbial contamination. The use of foil for such purposes would not be effective. Additionally, the concept of a phenol coefficient is used to determine the effectiveness of a disinfectant. If a disinfectant has a phenol coefficient greater than 1.0, it's more effective than phenol at killing microbes.