What does “proximity fuse” mean in artillery shells?

A proximity fuse refers to a device designed to detonate an artillery shell when it comes within a certain range of a target, rather than requiring direct contact for detonation. This capability significantly enhances the effectiveness of the artillery, allowing for detonation in the air above or near the target, which can create a larger area of effect and increase the chances of hitting moving or evasive targets. Proximity fuses are particularly useful against aircraft and targets that may not be directly hit by conventional fuses that require impact.

The other options do not accurately describe the function of a proximity fuse. For instance, the first choice pertains to a traditional impact fuse that requires the shell to strike the ground, while the third option describes a feature not associated with proximity fuses. The last choice discusses high altitude conditions, which is unrelated to the primary function of proximity detonation. Thus, the definition that specifies detonation in close range to the target captures the essence of a proximity fuse accurately.