Question

If $\lambda _{v} \, , \, \lambda _{x} \, , \, $ and $\, \lambda _{m}$ represent the wavelengths of visible light, X - rays and microwaves respectively, then

• A. $\lambda _{m}>\lambda _{x}>\lambda _{v}$
• B. $\lambda _{m}>\lambda _{v}>\lambda _{x}$
• C. $\lambda _{v}>\lambda _{x}>\lambda _{m}$
• D. $\lambda _{v}>\lambda _{m}>\lambda _{x}$

Answer 1

Answer: (B)

We know that energy in terms of wavelength $\lambda $ , Planck's constant $h$ and speed of light $c$ is given by $E=\frac{h c}{\lambda } \, $
From above, $\Rightarrow E \propto \frac{1}{\lambda }$
Since, $E_{m} < E_{v} < E_{x}$
$\therefore \, \, \, \lambda _{m}>\lambda _{v}>\lambda _{x}$