Define absolute refractive index of a medium. Light enters from air to water having refractive index 4/3. Find the absolute refractive index of a medium if the speed of light in vacuum is 3x 108 m/s.
Answers
Answer:
Absolute refractive index of a medium is the ratio of light's velocity in air/vacuum and light's velocity in that specific medium.
Water's ref. index = 4/3 (given)
=> 4/3 = (3 × 10^8 m/s)/(Light's velocity in water)
∴ Velocity of light in water = (3 × 10^8) ÷ 4/3
=> (3 × 10^8)*(3/4) (Dividing by a number is the same as multiplying by its reciprocal)
=> (3 × 3 × 10^8)/4
=> (9 × 10^8)/4
=> (9 × 100 × 10^6)/4
=> 9 × 25 × 10^6
=> 200 × 10^6 => 2 × 10^8 m/s is light's velocity in water.
Answer:
The ratio of speed of light in a vaccum/air to the speed of light in the given medium.
such that: n =c/v
Given-
refractive index of water (n) = 4/3
speed of light in air (c) = 3×10⁸ m/s
by applying the formula,
n = c/v (where v = speed of light in medium )
4/3 = 3×10⁸/v
v = 3×3×10⁸/4
v = 9×10⁸/4
v = 2.25×10⁸
Therefore, the speed of light in medium (v) =2.25×10⁸