Question

Why refractive index decreases with increase in wavelength

Answer 1

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step-by-step explanation:

We know that,

V =  λf ................(i)

where,

V = velocity

 λ = wavelength

f = frequency

and,

we also know that,

μ = c/V .....................(ii)

where,

μ = refractive index

c = speed of light in vaccum

V = velocity

Now,

putting the value of V from eqn (i) in eqn (ii),

we get,

μ = c/λf

From this eqn, we get

μ is inversely proportional to  λ

so,

as  λ increases, μ decreases.

Answer 2

step-by-step explanation:

We know that,

V =  λf ................(i)

where,

V = velocity

 λ = wavelength

f = frequency

and,

we also know that,

μ = c/V .....................(ii)

where,

μ = refractive index

c = speed of light in vaccum

V = velocity

Now,

putting the value of V from eqn (i) in eqn (ii),

we get,

μ = c/λf

From this eqn, we get

μ is inversely proportional to  λ

so,

as  λ increases, μ decreases.