Assertion (A): Sunlight reaches us without dispersion in the form of white light and not as its components.
Reason (R): Dispersion takes place due to variation of refractive index for different wavelengths but in vacuum the speed of light is independent of wavelength and hence vacuum is a non-dispersive medium.
Answer
For Assertion
- Dispersion only occurs after the sunlight enters the atmosphere at a minor rate.
- So sunlight reaches us without dispersion in the form of white light and not as its components.
- Therefore, the assertion is true.
For reasoning
- This happens because before entering the atmosphere, sunlight passes through vacuum
- In vacuum , light does not disperse
- In vacuum, all colours travel with the same speed.
Thus, Reasoning is also true.
Thus,
- Assertion is True
- Reasoning is True
- And the reason is the correct explanation for the assertion.
Correct option: (a)
