If the frequency of a wave is 20 H z , what is the period of the wave?

Answer

0.05 seconds

Q: What formula do we use to calculate the period of a wave? A: T = 1/f, where T is the period and f is the frequency.
Q: What is the value of the frequency given in the question? A: The frequency is 20 Hz.
T = 1/f, T = 1/20 Hz.
T = 0.05 seconds.