Short duration pulses also have a ______ length.

Short duration pulses also have a ______ length.

• A. Long
• B. Medium
• C. Variable
• D. Short

Answer: (D)

A pulse’s spatial length is tied to how long it lasts and how fast it travels. In a given medium where the propagation speed is constant, the distance the pulse occupies in space is L = velocity × duration. So if the pulse is short in time, the distance it covers while it exists is small, making the spatial length short. That’s why the best fill for the blank is “short.” If we tried “long,” it would clash with the idea that a shorter time span yields a smaller travel distance. “Medium” or “variable” aren’t determined by the duration alone in a single, uniform medium; they don’t describe the direct relationship between time width and spatial extent.

A pulse’s spatial length is tied to how long it lasts and how fast it travels. In a given medium where the propagation speed is constant, the distance the pulse occupies in space is L = velocity × duration. So if the pulse is short in time, the distance it covers while it exists is small, making the spatial length short. That’s why the best fill for the blank is “short.”

If we tried “long,” it would clash with the idea that a shorter time span yields a smaller travel distance. “Medium” or “variable” aren’t determined by the duration alone in a single, uniform medium; they don’t describe the direct relationship between time width and spatial extent.