Light from a HeNe Laser (632

Multiple Choice

Light from a HeNe laser (632.8 nm wavelength) is directed upon a human hair,in an attempt to measure its diameter by examining the diffraction pattern.The hair is mounted in a frame 7.5 m from a wall and the central diffraction maximum is measured to be 14.6 cm wide.What is the diameter of the hair?

A) 65 microns
B) 32.5 microns
C) 43.3 microns
D) 86.6 microns