Final answer:
The pulse duration is equal to the period multiplied by the number of cycles in the pulse. It represents the total amount of time for the pulse to complete all its cycles, based on the inverse relationship between frequency and period.
Step-by-step explanation:
The pulse duration of a wave is equal to the total amount of time it takes for a pulse to complete its cycle, which can be calculated as the period of the wave multiplied by the number of cycles in the pulse. It's important to understand the relationship between various wave properties to accurately determine the pulse duration. The key relationship here is that the period (ℓ) is the time taken for one complete cycle, and the frequency (ƒ) is the number of cycles per unit time.
Using these definitions, option D is correct: pulse duration is Period multiplied by the Number of Cycles in the Pulse. This is because the period gives the duration of one cycle, and multiplying it by the number of cycles will give the total time taken for all cycles in the pulse to occur.
The frequency is inversely related to the period, as the frequency is the number of repetitions (or cycles) that occur in a second, which can be written as ƒ = 1/ℓ. Moreover, the wavelength (λ) is determined by the wave speed (v) times the period, or it can be the wave speed divided by the frequency.