What is the difference between absolute refractive index and relative refractive index?

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Jasmine Grover

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The absolute refractive index and the relative refractive index are two different measures of the refractive properties of a material.

Absolute Refractive Index

The absolute refractive index, also known as the refractive index, is a measure of how much a material slows down light as it passes through it.

  • It is defined as the ratio of the speed of light in a vacuum to the speed of light in the material.
  • The absolute refractive index is denoted by the symbol "n", and it is a unitless quantity.
  • The absolute refractive index is a fundamental property of a material, and it depends on the chemical composition and physical structure of the material.

absolute and relative refractive index

Relative Refractive Index

The relative refractive index, on the other hand, is a measure of the difference in refractive index between two materials.

  • It is defined as the ratio of the absolute refractive index of one material to the absolute refractive index of another material.
  • The relative refractive index is denoted by the symbol "n", and it is a unitless quantity.
  • The relative refractive index is used to compare the refractive properties of different materials, and it is often used in optics and materials science.

In summary, the absolute refractive index is a measure of how much a material slows down light, while the relative refractive index is a measure of the difference in refractive index between two materials.

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CBSE CLASS XII Related Questions

  • 1.
    A student sets up the circuit as shown in the figure to find the value of unknown resistance X and records a set of readings of the voltmeter and the ammeter by using the rheostat.


      • 2.
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          • 3.
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              • The total charge of the two spheres is conserved.
              • Both spheres attain the same potential.
              • The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2)}{(r_1 + r_2)}$
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            • 4.
              Read the following paragraph and answer the questions that follow.
              A p-type or n-type semiconductor can be converted into a p-n junction by doping it with suitable impurity. The motion of majority charge carriers causes diffusion current across the junction while the barrier electric field causes motion of minority carriers for drift current. In case of unbiased diode, the diffusion and drift currents are equal. This equilibrium is disturbed by the biasing batteries. Diodes, therefore, allow currents in one direction. This property of diode is used in making rectifiers.


                • 5.
                  Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.


                    • 6.
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                        CBSE CLASS XII Previous Year Papers

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