The work functions of two photosensitive metal surfaces $A$ and $B$ are in the ratio $2: 3$. If $x$ and $y$ are the slopes of the graphs drawn between the stopping potential and frequency of incident light for the surfaces $A$ and $B$ respectively, then $x: y=$

Wave picture of light has failed to explain

The efficiency of a bulb of power 60 W is $16 \%$. The peak value of the electric field produced by the electromagnetic radiation from the bulb at a distance of 2 m from the bulb is $\left(\frac{1}{4 \pi \varepsilon_{0}}=9 \times 10^{9} \mathrm{Nm}^{2} \mathrm{C}^{-2}\right)$

The work function of a photosensitive metal surface is 1.1 eV . Two light beams of energies 1.5 eV and 2 eV incident on the metal surface. The ratio of the maximum velocities of the emitted photoelectrons is

The de-Broglie wavelength of a proton is twice the de-Broglie wavelength of an alpha particle. The ratio of the kinetic energies of the proton and the alpha particle is

If the de-Broglie wavelength of a neutron at a temperature of $77^{\circ} \mathrm{C}$ is $\lambda$, then the de-Broglie wavelength of the neutron at a temperature of $1127^{\circ} \mathrm{C}$ is

If Planck's constant is $6.63 \times 10^{-34} \mathrm{Js}$, then the slope of a graph drawn between cut-off voltage and frequency of incident light in a photoelectric experiment is

The de-Broglie wavelength of an electron accelerated between two plates having a potential difference of 900 V is nearly