If the refractive index for different medium are N1 = 1.5, n2 = 1.7 and n3 =2
respectively then choose the correct option?
I) Speed of the light in med1> speed of light in med - 2
ii) Speed of light in med-2> speed of light in med-1> speed of light med-3
iii) Speed of light med-1> Speed of light in med-2> speed of light in med 3.
iv) None of these.
Answers
iii) Speed of light med-1> Speed of light in med-2> speed of light in med 3.
Given that:
Refractive index of medium 1 = 1.5
Refractive index of medium 2 = 1.7
Refractive index of medium 3 = 2
Also, we know that, lesser the refractive index, greater the speed of light in that particular medium. That is, refractive index and velocity of light are inversely proportional. This will mean that the speed of light will be the greatest in medium 1, and the least in medium 3. The speed of light in medium 2 will fall between between that of medium 1 and 3.
Therefore, we can conclude that the third option is the correct answer as it clearly shows decreasing speed of light from medium 1 to medium 3.
Knowledge Bytes:
From the given set of refractive indices, we can infer that:
➡ Medium 1 is probably glass slab or benzene.
➡ Medium 2 is probably ruby.
➡ Medium 3 is probably boron nitride.