Newton's Disc

Q.

Consider the following reasons for the reddish appearance of the sun at the sunrise or the sunset:

1. Light from the sun near the horizon passes through thinner layers of air.
2. Light from the sun covers a larger distance of the earth’s atmosphere before reaching our eyes.
3. Near the horizon, most of the blue light and shorter wavelengths are scattered away by the particles.
4. Light from the sun near the horizon passes through thicker layers of air.

The correct reasons are:

1. i and iii only

2. ii, iii, and iv

3. i and ii only

4. iii and iv only

Q.

Give reasons for the following:

When yellow light falls on a blue object, it appears black?

Q.

In the atmosphere, which color of light gets scattered the least?

Q.

Why danger signals are red in color?

Q. The sun appears red during sunrise and sunset and not blue because of following reasons:

1. Blue light undergoes more scattering
2. Blue light has greater wavelength
3. Red light undergoes more scattering
4. Red light has greater wavelength

Q. Why don't we see the sunlight directly in its seven shades i.e., VIBGYOR?

Q.

The spectrum of sunlight consists of ___ prominent colours.

1. seven

2. three

3. two

4. five

Q.

At sunrise or at sunset the sun appears to be reddish while at midday it looks white. Explain.

Q. It was the British scientist _______who discovered in 1666 that light consists of seven colours. Fill in the blank.

1. Henry
2. John Dalton
3. Sir Issac Newton
4. Einstein

Q. The discovery of Newton's colour disc proves which of the following statement?

1. Light is colourless
2. Light is not colourless
3. Light has only 1 colour
4. Light has only 3 basic colours

Q. What does Newton's colour disc possess?

1. 7 segments in rainbow colours
2. 5 segments in rainbow colours
3. 4 segments in rainbow colours
4. 9 segments in rainbow colours

Q. Newton's colour disc was invented by whom?

1. Albert Einstein
2. Sir Isaac Newton and Faraday
3. Sir Isaac Newton and John Kennedy
4. Sir Isaac Newton

Q. How many colours comprises white light?

1. infinite
2. seven
3. three
4. fourteen

Q. Why don't we see the sunlight directly in its seven shades i.e., VIBGYOR?

Q.

Splitting of light into its component colours is known as:

1. Lateral Inversion

2. Dispersion

3. Refraction

4. Reflection

Q. If a newton's color disc composed of seven colors is rotated at high speed, it appears as

1. Seven coloured disc rotating
2. Few colours merge and only three dominant colours are visible
3. Colours mix and it appears white
4. Colours mix giving a sparkling effect

Q. What is meant by Newton’s disc. Explain with neat diagram.

Q.

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

1. Newton’s disc

2. Faraday’s disc

3. Rutherford’s disc

4. Galileo’s disc

Q.

What colour of light is obtained when we mix beams of light of all colour?

1. White

2. Blue

3. Green

4. Black

Q. Make Newton’s disc by painting the constituent colors of white color of white light in the same order and proportion. Give Reason.

Q. Consider the following statements:

1. White light on passing through a prism, disperses into seven colours, in a phenomenon called dispersion.


2. Different wavelengths of light are refracted at different angles in the same medium.

1. Both the statements are correct, and 2 is not the correct reason of 1.

2. Both the statements are correct, and 2 is the correct reason of 1.
3. Both statements are wrong.
4. Statement 1 is correct but statement 2 is not.

Q. Make Newton’s disc by painting the constituent colours of white col-our of white light in the same order and proportion.
In which colour does the disc appear when rotated fast?