Question

The following can be arranged in decreasing order of wave number as
$A$. Radio wave
$B$. Microwave
$C$. X-Ray
$D$. Visible Ray

• A. $A>B>D>C$
• B. $C>D>B>A$
• C. $A>B>C>D$
• D. $D>C>B>A$

Answer 1

The correct option is B $C>D>B>A$

The increasing order of wavelengths of the given waves is,

${\lambda }_C<{\lambda }_D<{\lambda }_B<{\lambda }_A$

We know that the wave number is given by,

$K\propto \frac{1}{\lambda }$

Therefore, the correct order of wave number is,

$C>D>B>A$

Hence, $\left(B\right)$ is the correct answer.