If the kinetic energy of a particle in motion is decreased by $36 \%$,the increase in de Broglie wavelength of the particle is (in $\%$)

$A$ proton when accelerated through a potential difference of $V$, has a de-Broglie wavelength $\lambda$ associated with it. If an $\alpha$-particle is to have the same de-Broglie wavelength $\lambda$, it must be accelerated through a potential difference of

Find the de Broglie wavelength associated with a Helium $(He)$ atom in Helium gas at room temperature $(27^{\circ}C)$ and $1$ atmospheric pressure.

Two particles of equal masses are moving with equal speeds at an angle $60^o$. The de-Broglie wavelength of these particles is $\lambda$. Find the de-Broglie wavelength of the particles in the frame of the centre of mass of the particles.

Of the following particles having the same kinetic energy,the one which has the largest de Broglie wavelength is

Photons of energy $4.5 \ eV$ are incident on a photosensitive material of work function $3 \ eV$. The de Broglie wavelength associated with the photoelectrons emitted with maximum kinetic energy is nearly (in $Å$)