Question #4e709

1 Answer
Jun 2, 2016

9 maxima measured from the normal

Explanation:

The equation for determining the orders of maxima seen is:

nlamda=dsintheta

Where

n= order of maxima (0,1,2,3..)
d= separation of slits in grating=1/(2times10^5)=5times10^-6m
theta =the angle at which the interference patterns are seen (measured normal to the grating)

lamda =wavelength = 625times10^-9m

The maximum angle(theta), that is possible is 90 degrees, and sin90^0=1

The largest possible order of maxima is therefore nlamda=d

So in this example:

n*(625times10^-9)=(5times10^-6)

n=8

Including the zero order this would give 9 maxima measured from the normal (in practice, 8 observed either side of the zero order central maxima)