Physics
The danger signal is red because its wavelength is the …………… and therefore it gets ………… the least.
- least, deviated
- longest, scattered
- longest, dispersed
- least, scattered
Answer
longest, scattered
Reason — When light passes through a medium, shorter wavelengths (such as blue and violet) are scattered more strongly than longer wavelengths (such as red and orange). Hence, red light is often used for danger signals to ensure visibility over longer distances.
Related Questions
The red colour of the sun at sunrise and sunset is due to which of the following phenomenon ?
- deviation
- dispersion
- both deviation and dispersion
- scattering
The sky in a direction other than that of the sun appears …………… to an observer on the moon.
- red
- blue
- orange
- black
When sunlight enters the earth's atmosphere, state which colour of light is scattered (i) the most, and (ii) the least.
A beam of blue, green and yellow light passes through the the Earth's atmosphere. Name the colour which is scattered (a) the least, (b) the most.