Factors Affecting Refractive Index

Title of investigation: To investigate the factors which affect the refraction.

Research question: To investigate how the different mediums affect the refractive index.

Background: The refraction of light is the wave bending while it travels to the medium with

different speed. The refractive index is a ratio between the speed of light in the medium and the

speed of light in vacuum or in the air. The Snell`s law states that going into the denser medium,

light slows down and bends toward the normal line, and going into the less denser material, light

seeds up and bends away from the normal line. The formula for calculating the refractive index is:

n=sin i/sin r, where the relationship is between sinus of angle of incidence and sinus of

There are some factors that affect the refractive index of medium as different mediums

(it can be different liquids and gases), the angle of incidence, the atmospheric pressure. In this

experiment I will investigate how the different mediums affect the reflective index.

Hypothesis: If I add the three different mediums into the double semicircular prism by order, place

it on the optical disk and direct the light from ray box to the double semicircular prism with these

liquids by order, then the biggest angle of refraction the glycerol and the lowest the ethanol will

have, because the glycerol has the highest density than the oil and ethanol, so according to the

Snell`s law as the light travels from less dense medium, in this case the air, to more dense medium

in this case the three different mediums, the refractive index is increases.

Variables:

-Dependent variable: the refractive index. I will measure the refractive index by using the formula

according to the Snell`s law, where sinus of angle of incidence is divided to the sinus of angle of

refraction. I will measure the angles by directing the light from the ray box to the optical disk,

where the exact angles of incidence and refraction will be