In some countries the AC frequency is 50 Hz. What is the time interval for one cycle at this frequency?
a. 0.0050 s
c. 2 s
b. 0.020 s
d. 50 s
Question 2
What is the cause of refraction of a wave traveling from one medium to another?
a. There is a frequency change due to the change in the medium
b. There is a speed change due to the change in the medium.
c. There is a change in wave amplitude due to the change in the medium.
d. None of the above are associated with refraction.