Final answer:
The duty factor increases when the pulse duration increases, and it can be calculated by dividing the pulse duration by the period of the pulse. The correct answer is option d, as the duty factor will increase by a factor of eight.
Step-by-step explanation:
In physics, duty factor is defined as the ratio of the pulse duration to the period of a pulse signal. When the pulse duration increases while the period remains constant, the duty factor also increases. The duty factor can be calculated by dividing the pulse duration by the period and multiplying by 100 to get a percentage.
For example, if the pulse duration is 2 microseconds and the period is 10 microseconds, the duty factor would be (2/10) * 100 = 20%. If the pulse duration increases to 4 microseconds, the duty factor would become (4/10) * 100 = 40%.
Therefore, the correct answer is option d. The duty factor will increase by a factor of eight.