Light of 4000 Å is incident on a circular hole of radius 3 cm. How many half-period zones are contained in the circle if the screen is placed at a distance of 0.5 m?

Light of 4000 Å is incident on a circular hole of radius 3 cm. How m

1.	Light of 4000 Å is incident on a circular hole of radius 3 cm. How many half-period zones are contained in the circle if the screen is placed at a distance of 0.5 m?
A.	25
B.	250
C.	2500
D.	25000
Answer» E.