Question

In electromagnetic spectra, the wave length and frequencies are inversely related. A radio can tune in to any station in the $7.5MHz$ to $12MHz$ band. Determine the corresponding wave length band.

Answer 1

Speed of an EM wave $c=3\times {10}^{8}m/s$

Wavelength of an EM wave $\lambda =\frac{c}{\nu }$

Corresponding wavelength for the frequency $7.5MHz$ , ${\lambda }_1=\frac{3\times {10}^8}{7.5\times {10}^6}$

$⟹$ ${\lambda }_1=40$ m

Corresponding wavelength for the frequency $12MHz$ , ${\lambda }_1=\frac{3\times {10}^8}{12\times {10}^6}$

$⟹$ ${\lambda }_2=25$ m

Thus wavelength band is $25$ m to $40$ m.