Question

Light travels through a substance at 1.97 x 10^8 m/s. What is the index of the liquid? What type of liquid is it?

Answer 1

n = 1.52

Index of the liquid = 1.52

The type of the liquid is Crown glass.

Explanation:

In finding the index of refraction, we use this formula

n = c/v

where n is the index of refraction

c is velocity of light in vacuum which is constant and is equivalent to $3 \times 10^{8} \mathrm{m} / \mathrm{s}$

v is the velocity of light in a particular medium

Here we use $1.97 \times 10^{8} \mathrm{m} / \mathrm{s}$

Using the formula,

n = c/v

n = $3 \times 10^{8} / 1.97 \times 10^{8}$

n = 1.52284264

n = 1.52

Thus, the index of the liquid is 1.52

Answer 2

The refractive index of the liquid is 1.52. The substance is a crown glass.

Explanation:

Given:

Velocity of light through the substance, v = 1.97 X 10⁸ m/s

Refractive index of the liquid, μ = ?

We know,

μ = $\frac{c}{v}$

where, c = velocity of light in air

            v = velocity of light in the substance

speed of light in air is 3 X 10⁸m/s

$= \frac{3 X 10^8}{1.97 X 10^8} \\\\= 1.52$

Therefore, refractive index of the liquid is 1.52. The substance is a crown glass.