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प्रश्न
Write Einstein’s photoelectric equation?
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उत्तर
Einstein’s photoelectric effect equation:
(NOTE: Use any one of three given equations)
hv = φ0 + K.E
where, h = Planck's constant, v = frequency of the incomig photons
φ0 = work function of the material and K.E = kinetic energy of the emitted electrons
or
`hv = phi_0 + 1/2 mv_max^2 `=
where,h = Planck's constant,v = frequency of the incoming photons
φo = work function of the material, 1/2 mv_max^2`kinetic energy of the emitted electrons
Vmax = maximum velocity of emitted electron
or
`1/2 mv_max^2 = h(v - v_o)`
where h = Planck's constant, v = frequency of the incoming photons
vo = threshold frequency, `1/2 mv_max^2= ` kinetic energy of the emitted electrons
vmax = maximum velocity of emitted electron
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संबंधित प्रश्न
The work function for a certain metal is 4.2 eV. Will this metal give photoelectric emission for incident radiation of wavelength 330 nm?
point out any two characteristic properties of photons on which Einstein’s photoelectric equation is based ?
The electric field at a point associated with a light wave is `E = (100 "Vm"^-1) sin [(3.0 xx 10^15 "s"^-1)t] sin [(6.0 xx 10^15 "s"^-1)t]`.If this light falls on a metal surface with a work function of 2.0 eV, what will be the maximum kinetic energy of the photoelectrons?
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
Consider the situation of the previous problem. Consider the faster electron emitted parallel to the large metal plate. Find the displacement of this electron parallel to its initial velocity before it strikes the large metal plate.
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
Use Einstein’s photoelectric equation to show how from this graph,
(i) Threshold frequency, and (ii) Planck’s constant can be determined.
There are materials which absorb photons of shorter wavelength and emit photons of longer wavelength. Can there be stable substances which absorb photons of larger wavelength and emit light of shorter wavelength.
A student performs an experiment on photoelectric effect, using two materials A and B. A plot of Vstop vs ν is given in Figure.
- Which material A or B has a higher work function?
- Given the electric charge of an electron = 1.6 × 10–19 C, find the value of h obtained from the experiment for both A and B.
Comment on whether it is consistent with Einstein’s theory:
What happens if photon energy is less than the work function?
How can maximum kinetic energy be written in terms of stopping potential \[V_0\]?
If the frequency is above the threshold, how does greater intensity affect the number of electrons emitted?
