Advertisements
Advertisements
प्रश्न
A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum kinetic energy of the emitted photoelectrons is ______.
विकल्प
3.0 × 10-20 J
6.0 × 10-20 J
4.5 × 10-20 J
9.0 × 10-20 J
Advertisements
उत्तर
A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum kinetic energy of the emitted photoelectrons is 6.0 × 10-20 J.
Explanation:
Given: λ = 663 nm, Φ0 = 1.5 eV
To Find: Max kinetic energy
We know that K.E. = `hf - phi_0`
K.E. = `(hc)/lambda - phi_0`
K.E. = `((6.62 xx 10^-34 xx 3 xx 10^8))/((663 xx 10^-9)) - 1.5 xx 1.6 xx 10^-19`
K.E. = `6 xx 10^-20` J
APPEARS IN
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?
Plot a graph showing the variation of photoelectric current with collector plate potential at a given frequency but for two different intensities I1 and I2, where I2 > I1.
Define the terms (i) ‘cut-off voltage’ and (ii) ‘threshold frequency’ in relation to the phenomenon of photoelectric effect.
Using Einstein’s photoelectric equation shows how the cut-off voltage and threshold frequency for a given photosensitive material can be determined with the help of a suitable plot/graph.
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.
How does one explain the emission of electrons from a photosensitive surface with the help of Einstein’s photoelectric equation?
Use Einstein's photoelectric equation to show how from this graph,
(i) Threshold frequency, and
(ii) Planck's constant can be determined.
Choose the correct answer from given options
Photons of frequency v are incident on the surface of two metals A and B of threshold frequency 3/4 v and 2/3 v, respectively. The ratio of maximum kinetic energy of electrons emitted from A to that from B is
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.
The photon emitted during the de-excitation from the first excited level to the ground state of a hydrogen atom is used to irradiate a photocathode in which the stopping potential is 5 V. Calculate the work function of the cathode used.
