Advertisements
Advertisements
प्रश्न
The photoelectric threshold wavelength of a metal is 230 nm. Determine the maximum kinetic energy in joule and in eV of the ejects electron for the metal surface when it is exposed to a radiation of wavelength 180 nm.
[Planck’s constant : h = 6.63 * 10-34 Js, Velocity of light : C = 3 * 108 m/s.]
Advertisements
उत्तर
λ0 = 230 nm = 230 × 10−9m,
λ = 180 nm = 180 × 10−9m,
h = 6.63 × 10−34 J s, c = 3 × 108
m/s, K.E. (in joule and eV) = ?
Now,

∴ The maximum kinetic energy of the ejected electron is 2.402 × 10−19 J.

∴ The maximum kinetic energy of the ejected electron is 1.5 eV.
APPEARS IN
संबंधित प्रश्न
The momentum of a photon of de Broglie wavelength 5000Å is _______.
[Planck’s constant = 6.63 x10-34 J.s.]
Find the value of energy of electron in eV in the third Bohr orbit of hydrogen atom.
(Rydberg's constant (R) = 1· 097 x 107m - 1,Planck's constant (h) =6·63x10-34 J-s,Velocity of light in air (c) = 3 x 108m/ s.)
Find the wave number of a photon having energy of 2.072 eV
Given : Charge on electron = 1.6 x 10-19 C,
Velocity of light in air = 3 x 108 m/s,
Planck’s constant = 6.63 x 10-34 J-s.
State two important properties of photon which are used to write Einstein’s photoelectric equation.
Define (i) stopping potential and (ii) threshold frequency, using Einstein’s equation and drawing necessary plot between relevant quantities.
A proton and a deuteron are accelerated through the same accelerating potential. Which one of the two has less momentum?
Give reasons to justify your answer.
Write its S.I. unit of (intensity of radiation)
With reference to the photoelectric effect, define threshold wavelength
According to Einstein’s model, the threshold frequency for a metal having work function ϕ0 is given by _________.
Which of the following graphs correctly represents the variation of maximum kinetic energy (Ek) of photoelectrons with the frequency (𝜈) of the incident radiation?
Plot a labelled graph of |Vs| where Vs is stopping potential versus frequency f of the incident radiation. State how will you use this graph to determine the value of Planck's constant?
In an inelastic collision, which of the following does not remain conserved?
Radiations of two photon's energy, twice and ten times the work function of metal are incident on the metal surface successively. The ratio of maximum velocities of photoelectrons emitted in two cases is:
According to Einstein's photoelectric equation, the plot of the kinetic energy of the emitted photoelectrons from a metal Vs the frequency of the incident radiation gives as straight the whose slope:
Einstein work on the photoelectric effect provided support for the eqn:-
If the energy of photon corresponding to a wavelength of 6000 A° is 3.32 × 10−19 J, the photon energy for a wavelength of 4000 A° will be ______.
The slope of frequency of incident light and stopping potential for a given surface will be
What will be wavelength of a photon of momentum 6.6 × 10–24 kgms–1?
Which of the following is/are true for cathode ray
The moment of a photon is given by
(i) A ray of light incident on face AB of an equilateral glass prism, shows minimum deviation of 30°. Calculate the speed of light through the prism.

(ii) Find the angle of incidence at face AB so that the emergent ray grazes along the face AC.
- Calculate the frequency of a photon of energy 6.5 × 10−19 J.
- Can this photon cause the emission of an electron from the surface of Cs of work function 2.14 eV? If yes, what will be the maximum kinetic energy of the photoelectron?
How does stopping potential in photoelectric emission vary if the intensity of the incident radiation increases?
How does stopping potential in photoelectric emission vary if the frequency of incident radiation decreases?
