The wavelength associated with an electron moving with a velocity of $10^8 \, cm/s$ is ........ $\mathop {\rm{A}}\limits^{\rm{o}} $.

If the wavelength of a photon is $2.2 \times 10^{-11} \ m$ and $h = 6.6 \times 10^{-34} \ J \ s$,then the momentum of the photon is:

$A$ proton and a $Li^{3+}$ nucleus are accelerated by the same potential. If $\lambda_{Li}$ and $\lambda_{P}$ denote the de Broglie wavelengths of $Li^{3+}$ and proton respectively,then the value of $\frac{\lambda_{Li}}{\lambda_{P}}$ is $x \times 10^{-1}$. The value of $x$ is ............
(Rounded off to the nearest integer)
(Mass of $Li^{3+} = 8.3 \times \text{mass of proton}$)

The de-Broglie equation is:

What is the characteristic of an electron microscope? On which principle is it based?

If the kinetic energy of an electron is increased four times,the wavelength of the de-Broglie wave associated with it would become