NIOS Class 10 Science Activity 15.5 Light Energy

This activity demonstrates that the colour of light remains unchanged when it passes from one medium to another. We have already learnt about refraction in Activity 15.4.

 

Light Energy Activity

This activity is based on the NIOS Class 10 Science and Technology (212) Chapter 15: Light Energy, Module 4.

 

Aim

To observe whether the colour of light changes when it passes from one medium to another.

Materials used

   1. Transparent plastic bucket

   2. Water

   3.  Red colour light bulb

Procedure

We take a transparent plastic bucket and fill it with water. We place a red-light bulb under the bucket.

 Now we dip our head into the bucket and look at the bulb through the water and observe the colour of the light.

Caution ⚠ - Perform this activity under a teacher/ guardian’s presence and guidance.

Observation

We observe that the red bulb appears red in colour. We do not see any colour change.

Explanation

When light passes from air into water, its speed and wavelength change, but its frequency remains constant.

The colour of light depends on its frequency, so the colour of light (red colour) remains unchanged.

Conclusion

We can conclude that the colour of light depends on frequency, and frequency does not change when light travels from one medium to another, so the colour of light does not change.

Frequently Asked Questions

   1. What happens to light when it enters from air into water?

Answer – The Speed and wavelength of light change when light enters from air to water.

   2. On what factor does the colour of light depend?

Answer – The colour of light depends on frequency.

   3. Which property of a light ray does not change when light travels from one medium to another?

Answer – Frequency of light ray

   4.  Does wavelength change when light enters another medium?

Answer – Yes, wavelength changes when light enters another medium.

   5. Why does the colour of the bulb remain the same in water?

Answer – Because the colour of light depends on frequency, and frequency does not change during refraction.