Light of wavelength $5.4\times {10}^7 \mathrm{m}$ falls on a photo-surface and causes the emission of electrons of maximum kinetic energy $2.1 \mathrm{eV}$ at a rate of ${10}^{15}$per second. The light is emitted by a $60 \mathrm{W}$ light bulb. Calculate the electric current that leaves the photo-surface.

Light of wavelength $5.4\times {10}^7 \mathrm{m}$ falls on a photo-surface and causes the emission of electrons of maximum kinetic energy $2.1 \mathrm{eV}$ at a rate of ${10}^{15}$per second. The light is emitted by a $60 \mathrm{W}$ light bulb. Determine the work function of the surface.

Light of wavelength $5.4\times {10}^7 \mathrm{m}$ falls on a photo-surface and causes the emission of electrons of maximum kinetic energy $2.1 \mathrm{eV}$ at a rate of ${10}^{15}$per second. The light is emitted by a $60 \mathrm{W}$ light bulb. Estimate the maximum kinetic energy of the electrons when the intensity of the light becomes $120 \mathrm{W}$.

Light of wavelength $5.4\times {10}^7 \mathrm{m}$ falls on a photo-surface and causes the emission of electrons of maximum kinetic energy $2.1 \mathrm{eV}$ at a rate of ${10}^{15}$per second. The light is emitted by a $60 \mathrm{W}$ light bulb. Estimate the current from the photo-surface when the intensity is $120 \mathrm{W}.$

State three aspects of the photoelectric effect that cannot be explained by the wave theory of light. For each, outline how the photon theory provides an explanation.

Light of wavelength $2.08\times {10}^{-7} \mathrm{m}$ falls on a photo-surface. The stopping voltage is $1.40 \mathrm{V}$. Outline what is meant by stopping voltage.

Light of wavelength $2.08\times {10}^{-7} \mathrm{m}$ falls on a photo-surface. The stopping voltage is $1.40 \mathrm{V}$. Calculate the largest wavelength of light that will result in emission of electrons from this photo-surface.

The intensity of light incident on a photo-surface is doubled while the wavelength of light stays the same. For the emitted electrons, discuss the effect of this, if any, on $\mathbf{i}$ the energy and $\mathbf{ii}$ the number.

To determine the work function of a given photo-surface, light of wavelength $2.3\times {10}^{-7} \mathrm{m}$ is directed at the surface and the stopping voltage, $V_s$, recorded. When light of wavelength $1.8\times {10}^{-7}\mathrm{m}$ is used, the stopping voltage is twice as large as the previous one. Determine the work function.