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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.
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Use Einstein’s photoelectric equation to show how from this graph,
(i) Threshold frequency, and (ii) Planck’s constant can be determined.
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
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The minimum energy required to remove an electron is called ______.
The wavelength of a photon needed to remove a proton from a nucleus which is bound to the nucleus with 1 MeV energy is nearly ______.
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If c is the velocity of light in free space, the correct statements about photon among the following are:
- The energy of a photon is E = hv.
- The velocity of a photon is c.
- The momentum of a photon, ρ = `(h v)/c`.
- In a photon-electron collision, both total energy and total momentum are conserved.
- Photon possesses positive charge.
Choose the correct answer from the options given below:
Which observation could classical wave theory not explain?
Which feature of photoelectric emission could classical wave theory not explain?
Which equation gives the energy of one photon?
In \[E=h\nu\], what does \[\nu\] represent?
Which expression gives the maximum kinetic energy of emitted photoelectrons?
What happens if photon energy is less than the work function?
Which expression gives the threshold frequency?
If the frequency is above the threshold, how does greater intensity affect the number of electrons emitted?
