Question

A radio station is emitting radiations of frequency $2\times {10}^4\text{Hz}$. If its frequency is doubled,

• A. Wavelength will be doubled
• B. Energy per quanta will be doubled
• C. Wavenumber will be halved
• D. All of these

Answer 1

The correct option is B Energy per quanta will be doubled

Given: $\text{Frequency}=2\times {10}^4\text{Hz}$
We know that, $\text{Frequency}\left(\nu \right)=\frac{c}{\lambda }$
On doubling the frequency, wavelength will be halved as the speed of light has to be constant.
Now, $E=h\nu$, where $h$ is Planck's constant
If we double the frequency, $E$ will be doubled.
$\text{Wavenumber}\stackrel{-}{\left(\nu \right)}=\frac{1}{\lambda }$

Since wavelength gets halved, wavenumber will be doubled.