Question #c4774

1 Answer
Mar 2, 2017

For violet #sf(theta=41^@)#

For blue #sf(theta=48.8^@)#

Explanation:

www.sciwebhop.net

For constructive interference to occur, the path difference must be an integral number of wavelengths.

This is AC on the diagram.

#:.##sf(sintheta=(nlambda)/d)#

There are 800 lines in 1 mm.

#:.##sf(d=1/800=1.25xx10^(-3)color(white)(x)"mm")#

#sf(d=1.25xx10^(-6)color(white)(x)"m")#

For violet light when #sf(n=2)#:

#sf(sintheta=(2xx410xx10^(-9))/(1.25xx10^(-6))=0.656)#

#sf(theta=41^@)#

For blue light when #sf(n=2)#:

#sf(sintheta=(2xx470xx10^(-9))/(1.25xx10^(-6))=0.752)#

#sf(theta=48.8^@)#