If a system has a clock with period T seconds, what is the relation to its frequency f?

If a system has a clock with period T seconds, what is the relation to its frequency f?

• A. f = 1 / T
• B. f = T
• C. f = 1 / (2T)
• D. f = T^2

Answer: (A)

Frequency tells how many cycles happen each second, while period is the time for one complete cycle. If each cycle lasts T seconds, then in one second you can fit 1/T cycles. So the frequency is the reciprocal of the period: f = 1/T. The units confirm this, since seconds^-1 equals hertz. If the period doubles, the frequency halves. For example, T = 0.01 s gives f = 100 Hz.

Frequency tells how many cycles happen each second, while period is the time for one complete cycle. If each cycle lasts T seconds, then in one second you can fit 1/T cycles. So the frequency is the reciprocal of the period: f = 1/T. The units confirm this, since seconds^-1 equals hertz. If the period doubles, the frequency halves. For example, T = 0.01 s gives f = 100 Hz.