Umakant biswal
Last Activity: 7 Years ago
dear rb
According to the Snell's Law
sinQ1/sinQ2=V1/V2
in figure Q1,Q2,V1 and V2 are angles and velocity of light respectively..
Lens in air
the refractive index is 1.5.
In your case:
lens is immersed in water.
straight light ray pass from glass to water at the right side of lens the refractive index for water and glass system is
velocity of light in water/velocity of light in glass
2.255*10^8/2*10^8=1.1275
more the refractive index more the light beam bend away from normal while travelling from high density medium to low density medium and hence focal length is less.
refractive index for lens immersed in water is less than that of lens in air, so according to the refractive index value focal length will shift.
in case 2 focal length is more than case 1.
HOPE IT CLEARS NOW
REGARDS
