prove laws of refraction using huygdnes principle
Answers
Answer:
Explanation:
Snell's law of refraction using Huygen's Principle:
Consider a plane wavefront AB incident on a surface PQ separating two media 1 and 2.
The medium 1 is a rarer medium of refractive index n
1
in which light travels with a velocity C
1
. The medium 2 is denser medium of refractive index n
2
in which light travels with a velocity C
2
.
The angle between the incident ray FA and the normal NA at the point of incidence A is equal to i.
The angle is also equal to the angle between the incident plane wavefront BA and the surface of separation PQ.
So ∠BAD is the angle of incidence of the incident plane wavefront AB.
Similarly, the angle between the refracted wavefront and the surface of separation PQ is equal to the angle of refraction r.
i.e. ∠ADC=r.
Consider the triangles BAD ACD figure above.
sini=sin∠BAD=
AD
BD
=
AD
C
1
r
sinr=sin∠ADC=
AD
AC
=
AD
C
2
r
sinr
sini
=
C
2
t
C
1
t
=
C
2
C
1
= constant
This constant is called the refractive index of the second medium (2) with respect to the first medium (1).
C
2
C
1
=
n
1
n
2
=1n
2
This equation proves the Snell's law.
Explanation:
Snell's law of refraction using Huygen's Principle : Consider a plane wavefront AB incident on a surface PQ separating two media 1 and 2. The angle between the incident ray FA and the normal NA at the point of incidence A is equal to i.