Question

Two lasers are shining on a double slit, with slit separation d. Laser 1 has a wavelength of d/20, whereas laser 2 has a wavelength of d/15. The lasers produce separate interference patterns on a screen a distance 6.00 m away from the slits.A. Which laser has its first maximum closer to the central maximum?B. What is the distance delta ymax-min between the first maxima (on the same side of the central maximum) of the two patterns?C. What is the distance Delta ymax-min between the second maximum of laser 1 and the third minimum of laser 2, on the same side of the central maximum?

Answer 1

Now

Using

ym = m x λ x L/d

therefore for each of first Max we have m =1

And laser 1 had

y = (d/20) x (6.0m)/d

y = 6.0m /20 = 0.3

Then laser 2 will be

y = 6.0m/15 = 0.4

y ( laser1 ) < y ( laser2 )

So the first maxima of laser 1 will be closer to the Central maxima

So

(0.4m -0 .3 m) = 0.1m

( C)

Now for laser 1 we say

y= 26.0 m / 20 = 0.6 m

Laser 2

We have

ym=(m+1/2) x λ x L/d

So

Because there is no central minimum the first minimum is at m = 0

We can way 3rd minimum is at m = 2

So

y = (2.5) x 6.0 / 15 = 1m

So

Δy= 1m - 0.6m = 0.4 m