Question

A pair of slits is located near a screen in such a way that light incident on the slits can form a double slit interference pattern on the screen.

1. Which of the following actions performed by itself would increase the angular position of the m = 4 maximum of the pattern (more than one answer may be correct)?

a.use light with a longer wavelength

b.use light with a shorter wavelength

c.increase the distance from the slits to the screen

d.decrease the distance from the slits to the screen

e.use slits which are farther apart

f.use slits which are closer together

2. Which of the following actions performed by itself would decrease the distance along the screen between the pattern's center and the m = 3 minimum of the pattern (more than one answer may be correct)?

a.use light with a longer wavelength

b.use light with a shorter wavelength

c.increase the distance from the slits to the screen

d.decrease the distance from the slits to the screen

e.use slits which are farther apart

f.use slits which are closer together

Answer 1

1. we know that the angular positionis d sin theta = m*Lmbda

d- slit separation , Lambda - wavelength , as the distance from slit to screen is very large then the waves would be parallel to each other

so the options are

  

   a..use light with a longer wavelength
  
   f.use slits which are closer together

2.

we know the distance from central finge to the mth fringe is B = m*Lambda*D/d

   D- distance between slits and screen
   d- slit separati0n
   Lambda - wavelength

so the answers are

   b.use light with a shorter wavelength
  
   d.decrease the distance from the slits to the screen
  
   e.use slits which are farther apart