Advertisements
Advertisements
Question
Why is the colour red used as a sign of danger?
Advertisements
Solution
In the visible light, the wavelength of red light is longest, the light of red colour is scattered least by the air molecules of the atmosphere and therefore the light of red colour can penetrate to a longer distance. Thus, red light can be seen from the farthest distance as compared to the other colours having the same intensity. Hence, it is used for danger signal so that the signal may be visible from the far distance even in fog, etc.
APPEARS IN
RELATED QUESTIONS
Which colour of white light travels fastest in glass?
In following figure shows a thin beam of white light from a source S striking on one face of a prism.
Complete the diagram to show effect of prism on the beam and to show what is seen on the screen.
In following diagram shows a thin beam of white light from a source S striking on one face of a prism.
A slit is placed in between the prism and the screen to pass only the light of green colour. What will you then observe on the screen?
Light of different colours is deviated through different angles by a prism. Explain the reason.
What is understood by the term dispersion of light? What is its cause?
Name the radiation of a wavelength longer than 8 × 10−7 m.
Explain, why quartz prism is required for obtaining the spectrum of ultra-violet light?
Draw a neat diagram to show the arrangement you would use to project a pure spectrum of white light on a screen.
