Question

Wie we obtin pronounce fiction with a single slit
of wavelength
Where of the lat width to the wavelength for a single slit, to have the first
in minimum w 45"?
mei (first minimun
q=sin 45°
Short Answer I (SAI) ( 2 MARKS Each )
1) What are Secondary sources? State Huygens' Principle
2) A Plane Wavefront of light of wavelength 5500 A.U. is incident on two slits in a
sorcon perpendicular to the direction of light rays. If the total separation of 10 bright
finnges on a screen 2 m away is 2 cm. Find the distance between the slits.​

Answer 1

Answer:

short answer

1.Huygen's principle states every point on the current wavefront acts as a source of secondary spherical waves. These secondary waves propagate outwards, in the forward direction, and a common tangent (an envelope) to all these waves constitute the new wavefront.

2.Location of bright fringes is given by 

xn=nλD/b

where

n: nth bright fringe, λ: wavelength, D: distance between slits and screen, b: slit width

Fringe width(β) is equal to the separation between two consecutive bright(or dark) fringes.

β=λD/b..(i)

Angular fringe width θ is the angle subtended by a fringe width at the slits.

∴θ=β/D..(ii)

From (i) and (ii),

θ=λ/b