Important Points and Formulas of class 7 Science Chapter-Light
Share
Important Points and Formulas of class 7 Science Chapter-Light
May 16, 2022, 16:45 IST
Class 7 Science Chapter-Light
It is a matter of common experience that the objects inside a dark room, which are invisible, become visible when the room is illuminated by a source of light. Thus, light can be defined as the external cause responsible for the sensation of vision.
The branch of Physics dealing with the nature and properties of light and vision is called optics
Nature of Light - Theories
The important theories are as follows:
- Newton's Corpuscular Theory
- Huygens' Wave Theory
- Maxwell's Electromagnetic Theory
- Planck's Quantum Theory
Newton's Corpuscular Theory
Huygen’s Wave Theory
In 1967 Christian Huygens proposed the wave theory of light. According to this, a luminous body is a source of disturbance in hypothetical medium called ether. The disturbance from the source is propagated in the form of waves through space and the energy is distributed equally in all directions. Even though this theory could satisfactorily explain several optical phenomena, the presence of ether could not be detected.
Maxwell's Electromagnetic Theory
Electromagnetic theory of light was put forward by James Clerk Maxwell in 1873. According to this theory, light consists of fluctuating electric and magnetic fields propagating in the form of electromagnetic waves. But this theory failed to explain the photoelectric effect.
Do solve questions given in the NCERT text book with the help of NCERT solutions for class 7 Science .
Find Below Short Notes of chapter-Light
