The phenomenon of change in the path of light when it passes from one medium to another
The incident ray, the refracted ray and the normal at the point of incidence all lie in the same plane
Sin i / Sin r = μ [refractive index of the second medium with respect to the first medium]
Also μ = c/v or v1/v2
μ = Real depth / Apparent depth
Light enters medium a, crosses medium b and then leaves from medium c, then aμc = aμb x bμc
When light travelling from denser to rarer medium is incident at an angle greater than the critical angle, it is reflected back in the denser medium.
Light should travel from denser to rarer medium.
Angle i > angle ic where ic is the critical angle.
When light travels from denser to rarer medium, then that angle of incidence for which angle of refraction is 90o
-μ1/u + μ2/v = (μ2 - μ1)/R
where μ1 and μ2 are refractive indices of rarer and denser mediums respectively
R is the radius of curvature of the spherical surface.
-μ2/u + μ1/v = (μ1 - μ2)/R
1/f = (μ - 1)(1/R1 - 1/R2)
Where μ is the refractive index of material of the lens
R1 and R2 are the radii of curvature of the two surfaces of the lens.
1/v - 1/u = 1/f
m = hi/ho = v/u
P = 1/f if f is in meters Units of P: Dioptre D
1/F = 1/f1 + 1/f2 => P = P1 + P2 and m = m1 x m2
1/F = 1/f1 + 1/f2 - d/f1f2
δ = (μ - 1) A for A < 10o (thin prism)
δ = (i1 + i2) - A for A > 10o
here i1 and i2 are angles of incidence and emergence
δv - δr = (μv - μr)A
A + δ = i + e
μ = (Sin(A + δm/2)) / Sin A/2
where δm is angle of minimum deviation
w = Angular dispersion/Mean dispersion = (μv - μr)/(μ - 1)
v and r refer to violet and red colors
μ refers to mean color wavelength (yellow)
m = 1 + D/f where D = least distance of distinct vision = 2.5 cm
The ratio of angle subtended at the eye by the final image to the angle subtended at the eye by the object where both the final image and object are situated at the least distance of distinct vision.
m = L/fo[1 + (D/fe)]
L is the length of the microscope tube
fo is the focal length of objective
fe is the focal length of the eye piece
The final image is formed at infinity
Magnifying power of an astronomical telescope in normal adjustment is defined as the ratio of the angle subtended at the eye by the final image to the angle subtended at the eye by the object directly when the final image and the object both lie at infinite distance from the eye.
m = fo/-fe
It is defined as the ratio of the angle subtended at the eye by the final image at the least distance of distinct vision to the angle subtended at the eye by the object at infinity, when seen directly
m = (fo/fe)(1 + fe/D)
m = fo/fe = (R/2)/fe
Resolving power = 1/d = (2μSinθ)/λ
where μ is the refractive index of the medium
λ is the wavelength of light
θ is half angle of the cone of light from thee point object to the objective lens
Resolving power = 1/dθ = D/1.22λ
where D is the diameter of the object lens
λ is the wave length of light
Angle i = angle r
Incident ray, reflected ray and the normal at the point of incidence all lie in the same plane
1/v + 1/u = 1/f
m = hi/ho= -v/u