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प्रश्न
In an experiment on the photoelectric effect, the slope of the cut-off voltage versus the frequency of incident light is found to be 4.12 × 10−15 Vs. Calculate the value of Planck’s constant.
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उत्तर
The slope of the cut-off voltage (V) versus frequency (v) of incident light is given as:
`V/v` = 4.12 × 10−15 Vs
V is related to frequency by the equation:
hv = eV
Where,
e = Charge on an electron = 1.6 × 10−19 C
h = Planck’s constant
∴ h = `e xx V/v`
= 1.6 × 10−19 × 4.12 × 10−15
= 6.592 × 10−34 Js
Therefore, the value of Planck’s constant is 6.592 × 10−34 Js.
संबंधित प्रश्न
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A small metal plate (work function φ) is kept at a distance d from a singly-ionised, fixed ion. A monochromatic light beam is incident on the metal plate and photoelectrons are emitted. Find the maximum wavelength of the light beam, so that some of the photoelectrons may go round the ion along a circle.
The minimum energy required to remove an electron is called ______.
- In the explanation of photo electric effect, we assume one photon of frequency ν collides with an electron and transfers its energy. This leads to the equation for the maximum energy Emax of the emitted electron as Emax = hν – φ0 where φ0 is the work function of the metal. If an electron absorbs 2 photons (each of frequency ν) what will be the maximum energy for the emitted electron?
- Why is this fact (two photon absorption) not taken into consideration in our discussion of the stopping potential?
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 does light consist of in Einstein’s explanation?
In \[E=h\nu\], what does \[E\] represent?
In \[E=h\nu\], what does \[h\] represent?
What condition must be met for photoelectric emission to occur?
What happens if photon energy is less than the work function?
Which expression gives the threshold frequency?
Which expression gives stopping potential \[V_0\] in terms of frequency?
Why does the maximum kinetic energy of photoelectrons increase when frequency increases?
If the frequency is above the threshold, how does greater intensity affect the number of electrons emitted?
