Question

The signal light for danger is red in colour. Which of the following principle/ principles is/are used in it?
$\left(P\right)$ The red coloured light scatters least by fog or smoke.
$\left(Q\right)$ The wavelength of red coloured light is about $1.8$ times more than that of blue.

• A. $P$ only
• B. $P$ and $Q$ both
• C. $Q$ only
• D. None of $P$ or $Q$

Answer 1

The correct option is B $P$ and $Q$ both

$\begin{array}{c}\text{The colour with rerigh wavelength could}\\ \text{be automatically and easily seen by the naked}\\ \text{eye.}\\ \text{so red with high wavelength is used to show}\\ \text{danger.}\\ \text{The wavelength of red coloured light is about}\\ \text{1.}8\text{times more than that of blue.}\\ \text{the red coloured light scatters least by}\\ \text{fog or smoke}\\ \text{so. Option}B\text{is correct}\end{array}$