How long does it take for the sun's rays to reach the earth?
The correct answer is 8 minutes.
- It takes 8 minutes to reach the earth.
Key Points
- Light is a form of energy which is propagated as electromagnetic waves.
- In the spectrum of electromagnetic waves, it lies between the ultra-violet and infra-red region and has a wavelength between 3900 Å to 7800 Å.
- light behaves as wave and particle both.
- Speed of light is maximum in vacuum and air (3×108 m/s).
- It is a transverse wave.
- It takes 8 min 19 s to reach on the earth from the sun.
- The light reflected from the moon takes 1.28 s to reach earth.
Additional Information
- Electromagnetic waves are transverse, hence light is a transverse wave.
- Wave nature of light explains rectilinear propagation, reflection, refraction, interference, diffraction and polarization of light.
- Refractive Index of a medium is defined as the ratio of the speed of light in a vacuum to the speed of light in the medium.
- Light is measured with two main alternative sets of units: radiometry consists of measurements of light power at all wavelengths, while photometry measures light with a wavelength.
