Question

Choose the correct option relating wavelengths of different parts of electromagnetic wave spectrum

• A. ${\lambda }_{\text{visible}}<{\lambda }_{\text{micro waves}}<{\lambda }_{\text{radio waves}}<{\lambda }_{\text{x-rays}}$
• B. ${\lambda }_{\text{radio waves}}>{\lambda }_{\text{micro waves}}>{\lambda }_{\text{visible}}>{\lambda }_{\text{x-rays}}$
• C. ${\lambda }_{\text{x-rays}}<{\lambda }_{\text{micro waves}}<{\lambda }_{\text{radio waves}}<{\lambda }_{\text{visible}}$
• D. ${\lambda }_{\text{visible}}>{\lambda }_{\text{x-rays}}>{\lambda }_{\text{radio waves}}>{\lambda }_{\text{micro waves}}$

Answer 1

The correct option is B ${\lambda }_{\text{radio waves}}>{\lambda }_{\text{micro waves}}>{\lambda }_{\text{visible}}>{\lambda }_{\text{x-rays}}$

$\because E=\frac{hc}{\lambda }$

The orderly arrangement of different parts of $EM$ wave in decreasing order of wavelength is as follows,

${\lambda }_{\text{radio waves}}>{\lambda }_{\text{micro waves}}>{\lambda }_{\text{IR}}>{\lambda }_{\text{visible}}>{\lambda }_{\text{UV}}>{\lambda }_{\text{x-rays}}>{\lambda }_{\text{gamma}}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(B\right)$ is the correct answer.