Question

A disc in which seven rainbow colours equally spread over an area, which on rotation, fades to white colour is called:

• A. Newton’s disc
• B. Rutherford’s disc
• C. Faraday’s disc
• D. Galileo’s disc

Answer 1

The correct option is A

Newton’s disc

Newton's disc is a disc with sectors which are painted in rainbow colours, i.e. violet, indigo, blue, green, yellow, orange and red, in that order. When the disc is rotated, the colors fade to white.
Isaac Newton used this disc to demonstrate that white light is a combination of the seven different colours found in a rainbow.