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=dsinthetanλ=dsinθ

Where

nn= order of maxima (0,1,2,3..)
dd= separation of slits in grating=1/(2times10^5)=5times10^-6m12×105=5×106m
thetaθ =the angle at which the interference patterns are seen (measured normal to the grating)

lamdaλ =wavelength = 625times10^-9m625×109m

The maximum angle(thetaθ), that is possible is 90 degrees, and sin90^0=1sin900=1

The largest possible order of maxima is therefore nlamda=dnλ=d

So in this example:

n*(625times10^-9)=(5times10^-6)n(625×109)=(5×106)

n=8n=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)