What are 2 characteristics that create pulses of short duration?

What are 2 characteristics that create pulses of short duration?

• A. Many cycles in the pulse; Short periods
• B. Many cycles in the pulse; Long periods
• C. Few cycles in the pulse; Long periods
• D. Few cycles in the pulse; Individual cycles with short periods

Answer: (D)

Short pulses come from a small amount of time packed into the waveform, which happens when the pulse contains only a few cycles and each cycle itself is brief. The duration of a pulse is essentially the number of cycles times the period of one cycle. So to achieve a short pulse you want both a small number of cycles and a short period. That’s why the best choice describes few cycles in the pulse and individual cycles with short periods. If you have many cycles, even with short periods, the pulse gets longer; if the periods are long, the pulse also lengthens. A statement about short periods alone doesn’t guarantee a short pulse if there are many cycles.

Short pulses come from a small amount of time packed into the waveform, which happens when the pulse contains only a few cycles and each cycle itself is brief. The duration of a pulse is essentially the number of cycles times the period of one cycle. So to achieve a short pulse you want both a small number of cycles and a short period. That’s why the best choice describes few cycles in the pulse and individual cycles with short periods. If you have many cycles, even with short periods, the pulse gets longer; if the periods are long, the pulse also lengthens. A statement about short periods alone doesn’t guarantee a short pulse if there are many cycles.