# Refractive index and concentration relationship questions

The refractive index has linear relationship with the concentration of sugar solution. Mathematical expressions were also derived for the wavelength dependent. The refractive index is a ratio of the speed of light in a medium relative to its The refractive index () can be calculated using the equation below. . This is a good webpage for the most common problems when setting up your refractometer. In addition, refractive indices are also used to determine the concentration of a. Study concepts, example questions & explanations for MCAT Physical the light is then directed into a glass cuvette containing an unknown concentration of protein. n is the index of refraction, c is the speed of light in a vacuum, and v is the speed of light We also know the relationship between velocity and wavelength.

Each measurement has taken three times.

Experimental set up for the measurements of angle of minimum deviation using prism spectrometer. Methods of measuring temperature dependent refractive The temperature dependent refractive indices of the solution measured at the temperatures The solutions were heated using magnetic stirrer with hot plate and its temperature controlled by placing the thermometer inside a solution.

The angle of minimum deviation was measured at the interval of 5 K while the solution is cooling down from highest to lowest temperature.

Calibration curve developed from the graph of refractive index versus temperature of the solution. Soft drink beverage solutions preparation In order to measure the sugar contents in soft drink beverages Pepsi, Coca, 7up, Sprite, Fanta and Mirinda each sample was poured into a beaker and stirred for minutes by magnetic stirrer to remove gases within the samples.

The refractive index of each solution was calculated from angle of minimum deviation using Equation 1.

The sugar contents in soft drink beverages were determined using eqns.

From experimental data we can find that RI of sugar solution increase linearly with the concentration. The difference in the slope value indicated the dependence of refractive index on the wavelength of laser light.

### Refractive index | Physics: Problems and Solutions | FANDOM powered by Wikia

Shows the refractive index versus concentrations of sugar solution using Red Diode, He-Ne and Green Diode laser in standard solutions. A comparison of our experimental results with the available literature data indicated that the results are quite similar with those previously reported by other authors [ 2 - 4 ].

Snell's Law & Index of Refraction - Wavelength, Frequency and Speed of Light

In Table the last two columns shows the refractive index of sucrose solutions reported using Abbe refractometer [ 4 ] and Sodium lamp at the wavelength As indicated in Table 1 our data and the previously reported results using different techniques are quite consistent with deviation of the order of Figure 3 displays the residual of the RI at different concentration of sugar solutions. Sometimes, a "group velocity refractive index", usually called the group index is defined: This value should not be confused with n, which is always defined with respect to the phase velocity.

At the microscale, an electromagnetic wave's phase velocity is slowed in a material because the electric field creates a disturbance in the charges of each atom primarily the electrons proportional to the permittivity of the medium. The charges will, in general, oscillate slightly out of phase with respect to the driving electric field.

The charges thus radiate their own electromagnetic wave that is at the same frequency but with a phase delay. The macroscopic sum of all such contributions in the material is a wave with the same frequency but shorter wavelength than the original, leading to a slowing of the wave's phase velocity.

Most of the radiation from oscillating material charges will modify the incoming wave, changing its velocity. However, some net energy will be radiated in other directions see scattering. If the refractive indices of two materials are known for a given frequency, then one can compute the angle by which radiation of that frequency will be refracted as it moves from the first into the second material from Snell's law.

Not thought to occur naturally, this can be achieved with so-called metamaterials and offers the possibility of perfect lenses and other exotic phenomena such as a reversal of Snell's law. The refractive index is a ratio of the speed of light in a medium relative to its speed in a vacuum.

## Refractive index

This change in speed from one medium to another is what causes light rays to bend. This is because as light travels through another medium other than a vacuum, the atoms of that medium constantly absorb and reemit the particles of light, slowing down the speed light travels at.

The refractive index can be calculated using the equation below. However, it is also important to note that light changes direction when it travels from one medium to another. The refractive index of any other medium is defined relative to the refractive index of a vacuum, which is assigned a value of 1. Thus, a refractive index of 1. The refraction of light. In this diagram, light travels faster in medium A than it does in medium B.

Refractive indices can be measured for different types of mediums including transparent or coloured solutions, turbid suspensions, emulsions, fine powders, ect. Factors that affect the refractive index: The two factors which affect the value of the refractive index are: