Advertisements
Advertisements
प्रश्न
A filter transmits only the radiation of wavelength greater than 440 nm. Radiation from a hydrogen-discharge tube goes through such a filter and is incident on a metal of work function 2.0 eV. Find the stopping potential which can stop the photoelectrons.
Advertisements
उत्तर
Wavelength of radiation coming from filter, λ = 440 nm
Work function of metal, ϕ = 2 eV
Charge of the electron, e = 1.6 × 10-9 C
Let V0 be the stopping potential.
From Einstein's photoelectric equation,
`(hc)/lamda - ø=eV_0`
Here,
h =Planck constant
c = Speed of light
λ = Wavelength of radiation
`(4.14 xx 10^-15xx3xx10^8)/(440xx10^-9)- 2eV = eV_0`
⇒ `eV_0 = ((1242)/440 - 2)eV = 0.823`
⇒ `V_0 = 0.823` Volts
APPEARS IN
संबंधित प्रश्न
Calculate the radius of Bohr’s fifth orbit for hydrogen atom
Explain, giving reasons, which of the following sets of quantum numbers are not possible.
- n = 0, l = 0, ml = 0, ms = + ½
- n = 1, l = 0, ml = 0, ms = – ½
- n = 1, l = 1, ml = 0, ms = + ½
- n = 2, l = 1, ml = 0, ms = – ½
- n = 3, l = 3, ml = –3, ms = + ½
- n = 3, l = 1, ml = 0, ms = + ½
Calculate the energy required for the process
\[\ce{He^+_{(g)} -> He^{2+}_{(g)} + e^-}\]
The ionization energy for the H atom in the ground state is 2.18 ×10–18 J atom–1
- Using the Bohr’s model, calculate the speed of the electron in a hydrogen atom in the n = 1, 2 and 3 levels.
- Calculate the orbital period in each of these levels.
State Bohr's postulate to define stable orbits in the hydrogen atom. How does de Broglie's hypothesis explain the stability of these orbits?
Using Bohr’s postulates, derive the expression for the frequency of radiation emitted when electron in hydrogen atom undergoes transition from higher energy state (quantum number ni) to the lower state, (nf).
When electron in hydrogen atom jumps from energy state ni = 4 to nf = 3, 2, 1, identify the spectral series to which the emission lines belong.
The electron in hydrogen atom is initially in the third excited state. What is the maximum number of spectral lines which can be emitted when it finally moves to the ground state?
The Bohr radius is given by `a_0 = (∈_0h^2)/{pime^2}`. Verify that the RHS has dimensions of length.
A positive ion having just one electron ejects it if a photon of wavelength 228 Å or less is absorbed by it. Identify the ion.
A beam of light having wavelengths distributed uniformly between 450 nm to 550 nm passes through a sample of hydrogen gas. Which wavelength will have the least intensity in the transmitted beam?
According to Bohr, 'Angular momentum of an orbiting electron is quantized'. What is meant by this statement?
Mention demerits of Bohr’s Atomic model.
The energy associated with the first orbit of He+ is ____________ J.
For an electron in the second orbit of hydrogen, what is the moment of momentum as per the Bohr's model?
Use Bohr's postulate to prove that the radius of nth orbit in a hydrogen atom is proportional to n2.
The energy required to remove the electron from a singly ionized Helium atom is 2.2 times the energy required to remove an electron from Helium atom. The total energy required to ionize the Helium atom completely is ______.
What is the energy associated with first orbit of Li2+ (RH = 2.18 × 10-18)?
Calculate the radius of the second orbit of He+.
Energy and radius of first Bohr orbit of He+ and Li2+ are:
[Given RH = −2.18 × 10−18 J, a0 = 52.9 pm]
