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Dispersion of Light Through a Prism

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Aim

To observe the dispersion of white light by a glass prism and understand the formation of spectrum.

Materials Required

Glass prism
White light source
Screen
Darkened room

Procedure

  1. Place the prism on a table in a darkened room.
  2. Allow a narrow beam of white light to pass through a slit and strike one face of the prism.
  3. Place a screen on the other side of the prism.
  4. Adjust the angle of the prism to obtain a clear spectrum on the screen.
  5. Observe the band of colors formed on the screen (VIBGYOR).

Precautions

  • The room should be dark to observe the spectrum clearly.
  • The slit should be very narrow to get a sharp spectrum.
  • The prism faces should be clean and free from smudges.

Observation Table

S.No. Color Approx. Wavelength (nm) Deviation Angle (δ) Position in Spectrum
Turn on the light to see observations

📹 Experiment Video

1. Which color deviates the most?

2. The correct order of spectrum is:

3. Dispersion occurs because:

4. A rainbow is formed by:

5. Which color has the longest wavelength?

Lab Report

Aim: To observe the dispersion of white light by a glass prism and understand the formation of spectrum.

Result: White light is composed of seven colors (VIBGYOR). The prism disperses light because each color has a different refractive index in glass.

Recorded Observations

Please run the simulation to populate observations.