Pulse duration is ______ to the frequency.

Pulse duration is ______ to the frequency.

• A. Directly proportional
• B. Inversely proportional
• C. Not related
• D. Quadratically proportional

Answer: (B)

The idea being tested is how the length of a pulse in time relates to the frequencies that make up that pulse. A shorter pulse exists for a shorter time, which requires a broader range of frequency components to shape the sharp edges. In simple terms, as the pulse gets shorter in time, the frequency content that defines it becomes broader, and the characteristic time scale is roughly the inverse of the frequency. That’s why pulse duration is inversely proportional to frequency: shorter durations correspond to higher frequency content, while longer durations correspond to lower frequency content.

The idea being tested is how the length of a pulse in time relates to the frequencies that make up that pulse. A shorter pulse exists for a shorter time, which requires a broader range of frequency components to shape the sharp edges. In simple terms, as the pulse gets shorter in time, the frequency content that defines it becomes broader, and the characteristic time scale is roughly the inverse of the frequency. That’s why pulse duration is inversely proportional to frequency: shorter durations correspond to higher frequency content, while longer durations correspond to lower frequency content.