(C) From the given $I - V$ curve,the stopping potential $V_s = 5 \, V$ and the saturation current $I_s = 10 \, \mu A = 10^{-5} \, A$.The energy of inc

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(C) From the given $I - V$ curve,the stopping potential $V_s = 5 \, V$ and the saturation current $I_s = 10 \, \mu A = 10^{-5} \, A$.The energy of incident photons is given by Einstein's photoelectric equation:$E = h\nu = eV_s + \phi_0$$E = 5 \, eV + 2 \, eV = 7 \, eV$.The saturation current is related to the power $P$ of the incident light by:$I_s = \eta \times \left( \frac{P}{E} \right) \times e$where $\eta$ is the efficiency of photoemission $= 10^{-3} \% = 10^{-5}$.Substituting the values:$10^{-5} = 10^{-5} \times \left( \frac{P}{7 \, eV} \right) \times e$$1 = \frac{P}{7 \, eV} \times e$$1 = \frac{P}{7}$$P = 7 \, W$.

Class 12 Physics Dual Nature of Radiation and Matter Einstein's Photoelectric Equation and Energy Quantum of Radiation

Medium

In the photoelectric experiment,if we use a monochromatic light,the $I - V$ curve is as shown. If the work function of the metal is $2 \, eV$,estimate the power of light used in $W$.
(Assume efficiency of photoemission $= 10^{-3} \%$,i.e.,the number of photoelectrons emitted is $10^{-3} \%$ of the number of photons incident on the metal.)

A
$2$
B
$5$
C
$7$
D
$10$

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Dual Nature of Radiation and Matter

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Einstein's Photoelectric Equation and Energy Quantum of Radiation

When light of intensity $1 \ W/m^2$ and wavelength $5 \times 10^{-7} \ m$ is incident on a surface, it is completely absorbed. If $100$ photons emit one electron and the surface area is $1 \ cm^2$, what is the photoelectric current?

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The work function of a metal is $1.6 \times 10^{-19} \, J$. When the metal surface is illuminated by light of wavelength $6400 \, \mathring{A}$,the maximum kinetic energy of the emitted photo-electrons will be. (Planck's constant $h = 6.4 \times 10^{-34} \, Js$)

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Two incident radiations having energies two times and ten times of the work function of a metal surface,produce photoelectric effect. The ratio of maximum velocities of emitted photoelectrons respectively is

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Radiation of two photon energies,twice and five times the work function of a metal,are incident successively on the metal surface. The ratio of the maximum velocity of photoelectrons emitted in the two cases is:

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Two light waves of wavelengths $600 \,nm$ and $200 \,nm$ are incident on a metal surface. The maximum velocity of photoelectrons produced due to one wavelength is $\frac{1}{3}$ of the maximum velocity of the photoelectrons produced due to the other wavelength. The work function of the metal is:

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When light of intensity $1 \ W/m^2$ and wavelength $5 \times 10^{-7} \ m$ is incident on a surface, it is completely absorbed. If $100$ photons emit one electron and the surface area is $1 \ cm^2$, what is the photoelectric current?

The work function of a metal is $1.6 \times 10^{-19} \, J$. When the metal surface is illuminated by light of wavelength $6400 \, \mathring{A}$,the maximum kinetic energy of the emitted photo-electrons will be. (Planck's constant $h = 6.4 \times 10^{-34} \, Js$)

Two incident radiations having energies two times and ten times of the work function of a metal surface,produce photoelectric effect. The ratio of maximum velocities of emitted photoelectrons respectively is

Radiation of two photon energies,twice and five times the work function of a metal,are incident successively on the metal surface. The ratio of the maximum velocity of photoelectrons emitted in the two cases is:

Two light waves of wavelengths $600 \,nm$ and $200 \,nm$ are incident on a metal surface. The maximum velocity of photoelectrons produced due to one wavelength is $\frac{1}{3}$ of the maximum velocity of the photoelectrons produced due to the other wavelength. The work function of the metal is:

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