Snells law Calculator

Introduction

Snell’s Law describes the relationship between the angles of incidence and refraction when light passes through a boundary of two different isotropic materials. It is also called the Law of Refraction. Using our Snells Law Calculator, we can calculate the angle of incidence, angle of refraction, or the refractive indices of the media.

Snell’s law states that given light passing through two different isotropic media, the ratio of the angle of incidence to the sign of the angle of refraction is equal to the inverse ratio of the refractive indices.

How to use the Snells Law Calculator?

Using Snell’s Law Calculator, we can calculate the angle of incidence, angle of refraction, or the refractive indices of the media.

The variables in our Snells law calculator include

Refractive Index (na) The index of refraction of material with Incident light

Angle of Incidence (θa) The angle of incidence as measured from the normal

Refractive Index (nb) The index of refraction of material with Refracted light

Angle of Refraction (θb) The angle of refraction as measured from the normal

What is Snells Law?

When light travels from one medium to another, it bends or refracts into the medium, and the same thing happens when the light exits the medium, it bends or refracts.

This happens because light travels slower in the material than in a vacuum. And the ratio of the speed of light in a vacuum and the material gives us the index of refraction or refractive index of the material.

n = \dfrac{c}{v}

Where,

c → Speed of light in vacuum

v → Speed of light in the material

n → Index of refraction of an optical material

The incident ray, reflected ray, refracted ray and the normal to the surface all lie in the same plane, called the plane of incidence.

The laws of refraction and reflection are

The angle of reflection is equal to the angle of incidence for all wavelengths and for any pair of mediums.

\theta_r = \theta_a

the ratio of signs of the angle of incidence and the angle of refraction is equal to the inverse ratio of the two refractive indices of the material.

How is Snells Law Calculated?

We can calculate the Snells Law by using the following formula

\dfrac{\text{sin} \;\theta_a}{\text{sin} \;\theta_b} = \dfrac{n_b}{n_a}

Where,

na → Refractive Index of material with Incident light

nb → Refractive Index of material with Refracted light

θa → Angle of incidence measured from the normal

θb → Angle of refraction measured from the normal

FAQs

How does the angle of incidence and refraction relate to Snell’s Law?

Snell’s Law states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. Hence the angle of incidence and angle of refraction are related. The angle of incidence is the angle formed by incoming light and the normal to the boundary, whereas the angle of refraction is formed by refracted light and the normal to the boundary.

How does Snell’s Law differ from the law of reflection?

Both Snell’s Law and the law of reflection explain the behaviour of light. However, they are not the same. The angle of incidence equals the angle of reflection, according to the law of reflection. However, Snell’s Law stipulates that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant.

How does the refractive index relate to Snell’s Law?

The refractive index is a constant related to Snell’s Law, defined as the ratio of the speed of light in a vacuum to the speed of light in a specific substance. In Snell’s Law, we use the refractive index to compute the angles of incidence and refraction.

How is Snell’s Law used in real-world situations?

We used Snell’s law to understand how light travels in different media. It finds its use, particularly in manufacturing eyewear, lenses, mirrors, and cameras. Fiber optics is one of the main real-life applications of Snell’s law. Similarly, we also use Snell’s law to examine the concentration of fluids.