If frequency increases while keeping other factors constant, pulse duration will

If frequency increases while keeping other factors constant, pulse duration will

• A. Decrease
• B. Increase
• C. Remain the same
• D. Double

Answer: (A)

The duration of a pulse depends on how long each cycle lasts and how many cycles the pulse contains. The time for one cycle is T = 1/f. If a pulse is defined by a fixed number of cycles, say N cycles, then its duration is PD = N × T. So when frequency increases while keeping that constant, the cycle time gets shorter and the total pulse duration gets shorter as well. For example, with 3 cycles per pulse: at 1 kHz, PD ≈ 3 × 1 ms = 3 ms; at 3 kHz, PD ≈ 3 × 0.333 ms ≈ 1 ms. Hence, pulse duration decreases as frequency increases. The other options would require changing the number of cycles or how the pulse is defined, which isn’t the case here.

The duration of a pulse depends on how long each cycle lasts and how many cycles the pulse contains. The time for one cycle is T = 1/f. If a pulse is defined by a fixed number of cycles, say N cycles, then its duration is PD = N × T. So when frequency increases while keeping that constant, the cycle time gets shorter and the total pulse duration gets shorter as well.

For example, with 3 cycles per pulse: at 1 kHz, PD ≈ 3 × 1 ms = 3 ms; at 3 kHz, PD ≈ 3 × 0.333 ms ≈ 1 ms. Hence, pulse duration decreases as frequency increases. The other options would require changing the number of cycles or how the pulse is defined, which isn’t the case here.