The electron microscope is based on the principle of

An electron of mass $m$ and a photon have the same energy $E$. The ratio of the de-Broglie wavelengths associated with them is:

The kinetic energy of a free electron increases to $3$ times the previous kinetic energy $(K.E.)$. The ratio of the new de-Broglie wavelength to the previous de-Broglie wavelength is:

$A$ proton is accelerated through $225 \,V$. Its de Broglie wavelength is ........ $nm$.

For a moving cricket ball,which of the following statements regarding the de-Broglie wavelength is correct?

The de Broglie wavelength associated with a proton changes by $0.25\%$. If its momentum changes by $p_0$,then its initial momentum is ......