Question

Chapter: Interference and diffraction.

Explain:

a/ Does light act like a wave?

b/ Does apply for this situation?

y L sino = L m2

c/ How thick of an object is that affects the interference and diffraction?

d/What do you think about the small angle? d sin θ = mλ. Why sin θ = tan θ?

Answer 1

a ) Solution -

Yes , Light is an electromagnetic wave and it propagate in longitudenal and transverse direction . The transverse nature of the light can be explained by the phenomenon of polarization and there are some phenomenon that can not be experienced by the ray nature of light can be explained by the wave nature of light like the interference and diffraction phenomenon.

To explain the phenomenon of interference and diffraction we have to consider the light as wave and ray nature can not explain these phenomenon.

b ) Solution -

Yes , these equations applies for the path difference of the wave and fringe width equations of the interference and diffraction patterns .

c) Solution -

Thickness of the object changes the fringe width ( lesser for the the thicker and higher refractive index objects ) as well as the location of the fringes will shift from orignal position and the whole interference and diffraction pattern will shift as well .

d) Solution -

The small angle has been taken into the consideration because the value of distance between slits (d) is very much smaller than the distance of the screen from the slit (D) so due to which the angle at the position of fringe becomes very small and hence at the small angles the value of $\sin \Theta$ = $\tan \Theta$ .