JEE Questions for Physics Atoms And Nuclei Quiz 8 - MCQExams.com

If the atom 100Fm257 follows the Bohr model and the radius of 100Fm257 is n times the Bohr’s radius, then find n.
  • 100
  • 200
  • 4

  • Physics-Atoms and Nuclei-62693.png
For uranium nucleus, how does its mass vary with volume?
  • m ∝ V
  • 2)
    Physics-Atoms and Nuclei-62695.png

  • Physics-Atoms and Nuclei-62696.png
  • m ∝ V2
A nucleus with mass number 220 initially at rest, emits an alpha particle. If the Q value of the reaction is 5.5 MeV, calculate the K.E. of the α particle.
  • 4.4 MeV
  • 5.4 MeV
  • 5.6 MeV
  • 6.5 MeV
The nuclei of which one of the following pairs of nuclei are isotones?

  • Physics-Atoms and Nuclei-62698.png
  • 2)
    Physics-Atoms and Nuclei-62699.png

  • Physics-Atoms and Nuclei-62700.png

  • Physics-Atoms and Nuclei-62701.png
Fission of nuclei is possible because the binding energy per nucleon in them
  • decreases with mass number at low mass numbers
  • increases with mass number at low mass numbers
  • decreases with mass number at high mass numbers
  • Increase with mass number at high mass numbers.
The total energy of an electron in the first excited state of hydrogen atom is about – 3.4 eV. Its kinetic energy in this state is:
  • -6.8 eV
  • 3.4 eV
  • 6.8 eV
  • -3.4 eV
Starting with a sample of pure 66Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is

  • Physics-Atoms and Nuclei-62702.png
  • 5 minutes
  • 15 minutes
  • 10 minutes

Physics-Atoms and Nuclei-62704.png
  • 5 fermi
  • 4 fermi
  • 8 fermi
  • 6 fermi
Fig. shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?
Physics-Atoms and Nuclei-62706.png
  • II
  • I
  • IV
  • III
If a star can convert all the He nuclei completely into oxygen nuclei, the energy released per oxygen nucleus is [Mass of He nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu]
  • 7.6 MeV
  • 56.12 MeV
  • 10.24 MeV
  • 23.9 MeV
A radioactive material has a half life of 10 days. What fraction of the material would remain after 30 days?
  • 0.5
  • 0.25
  • 0.125
  • 0.33
Which of the following is not conserved in nuclear reactions?
  • total energy
  • mass number
  • charge number
  • number of fundamental particles
In a sample of radioactive material, what fraction of the initial number of active nuclei will remain undisintegrated after half of a half life of the sample?

  • Physics-Atoms and Nuclei-62710.png
  • 2)
    Physics-Atoms and Nuclei-62711.png

  • Physics-Atoms and Nuclei-62712.png

  • Physics-Atoms and Nuclei-62713.png
A radioactive nucleus is being produced at a constant rate ∝ per second. Its decay constant is λ. If N0 are the number of nuclei at time t = 0, then the maximum number of nuclei possible are

  • Physics-Atoms and Nuclei-62715.png
  • N0

  • Physics-Atoms and Nuclei-62716.png

  • Physics-Atoms and Nuclei-62717.png
The binding energies of nuclei X and Y are E1 and E2 respectively. Two atoms of X fuse to give one atom of Y and an energy Q is released. Then
  • Q = 2E1 – E2
  • Q > (E2 – 2E1)
  • Q < (2E1 – E2)
  • Q = E2 – 2E1
The binding energy of an electron in the ground state of He is equal to 24.6 eV. The energy required to remove both the electrons is
  • 49.2 eV
  • 24.6 eV
  • 38.2 eV
  • 79.0 eV
A particle of mass 3 m at rest decays into two particles of masses m and 2m having non zero velocities. The ratio of the de-Broglie wavelength of the particles (λ1/λ2) is
  • 1
  • 2
  • 3
  • 1/2
The order of energies of energy levels A, B and C is EA < EB < EC. If the wavelength corresponding to transitions C → B, B → A and C→ A are λ1, λ2 and λ3 respectively, then which of the following relation is correct?

  • Physics-Atoms and Nuclei-62720.png
  • 2)
    Physics-Atoms and Nuclei-62721.png

  • Physics-Atoms and Nuclei-62722.png

  • Physics-Atoms and Nuclei-62723.png
The energy required to excite an electron from n = 2 to n = 3 energy level is 47.2 eV. The charge no. of the nucleus, around which the electron is revolving will be
  • 5
  • 10
  • 15
  • 20
The ratio (R) of the rate of production of neutrons to the rate of leakage of neutrons from a spherical body of uranium of radius r is proportional to
  • R ∝ r
  • 2)
    Physics-Atoms and Nuclei-62726.png
  • R ∝ r2

  • Physics-Atoms and Nuclei-62727.png
The nucler of which of following Pairs of nuclei are isotones

  • Physics-Atoms and Nuclei-62729.png
  • 2)
    Physics-Atoms and Nuclei-62730.png

  • Physics-Atoms and Nuclei-62731.png

  • Physics-Atoms and Nuclei-62732.png
when u-238 nucleus originally at lest decay by emitting an α -particle having a speed u the recoil speed of the resi - dual nucleus is.

  • Physics-Atoms and Nuclei-62734.png
  • 2)
    Physics-Atoms and Nuclei-62735.png

  • Physics-Atoms and Nuclei-62736.png

  • Physics-Atoms and Nuclei-62737.png
The energy difference between the first two levels of hydrogen atom is 10.2 eV. what is the corresponding energy difference for a singly ionised helium atom?
  • 10.2 eV
  • 81.6 eV
  • 20.4 eV
  • 40.8 eV
If in nature there may not be an element for which the principal quantum number n > 4, then the total possible number of elements will be
  • 60
  • 32
  • 4
  • 64
In the following atoms and molecules for the transition from n = 2 to n = 1, the spectral line of minimum wavelength will be produced by
  • Hydrogen atom
  • Deuterium atom
  • Uni-ionized helium
  • di-ionized lithium
First Bohr radius of an atom with Z = 82 is R. Radius of its third orbit is
  • 9R
  • 6R
  • 3R
  • R
The size of an atom is of the order of
  • 10–8 m
  • 10–10 m
  • 10–12 m
  • 10–14 m
Which one of the series of hydrogen spectrum is in the visible region?
  • Lyman series
  • Balmer series
  • Paschen series
  • Bracket series
The spectral series of the hydrogen atom that lies in the visible region of the electromagnetic spectrum
  • Paschen
  • Balmer
  • Lyman
  • Brackett
The kinetic energy of the electron in an orbit of radius r in hydrogen atom is (e = electronic charge)

  • Physics-Atoms and Nuclei-62743.png
  • 2)
    Physics-Atoms and Nuclei-62744.png

  • Physics-Atoms and Nuclei-62745.png

  • Physics-Atoms and Nuclei-62746.png
The ratio of the energies of the hydrogen atom in its first to second excited state is
  • 1/4
  • 4/9
  • 9/4
  • 4
An electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom. Given the Rydberg\'s constant R = 105 cm-1. The frequency in Hz of the emitted radiation will be

  • Physics-Atoms and Nuclei-62749.png
  • 2)
    Physics-Atoms and Nuclei-62750.png

  • Physics-Atoms and Nuclei-62751.png

  • Physics-Atoms and Nuclei-62752.png
According to Bohr\'s theory the radius of electron in an orbit described by principal quantum number n and atomic number Z is proportional to

  • Physics-Atoms and Nuclei-62754.png
  • 2)
    Physics-Atoms and Nuclei-62755.png

  • Physics-Atoms and Nuclei-62756.png

  • Physics-Atoms and Nuclei-62757.png
The radius of electron\'s second stationary orbit in Bohr\'s atom is R. The radius of the third orbit will be
  • 3 R
  • 2.25R
  • 9R

  • Physics-Atoms and Nuclei-62759.png
In any Bohr orbit of the hydrogen atom, the ratio of kinetic energy to potential energy of the electron is
  • 1/2
  • 2
  • –1/2
  • –2
Figure shows the energy levels P, Q, R, S and G of an atom where G is the ground state. A red line in the emission spectrum of the atom can be obtained by an energy level change from Q to S. A blue line can be obtained by following energy level change
Physics-Atoms and Nuclei-62762.png
  • P to Q
  • Q to R
  • R to S
  • R to G
The figure indicates the energy level diagram of an atom and the origin of six spectral lines in emission (e.g., line no. 5 arises from the transition from level B to A). Which of the following spectral lines will also occur in the absorption spectra?
Physics-Atoms and Nuclei-62764.png
  • 1, 4, 6
  • 4, 5, 6
  • 1, 2, 3
  • 1, 2, 3, 4, 5, 6
When a hydrogen atom is raised from the ground state to an excited state
  • P.E. increases and K.E. decreases
  • P.E. decreases and K.E. increases
  • Both kinetic energy and potential energy increase
  • Both K.E. and P.E. decrease
An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. The wave number of the emitted radiations (R = Rydberg\'s constant) will be

  • Physics-Atoms and Nuclei-62766.png
  • 2)
    Physics-Atoms and Nuclei-62767.png

  • Physics-Atoms and Nuclei-62768.png

  • Physics-Atoms and Nuclei-62769.png
In Bohr model of the hydrogen atom, the lowest orbit corresponds to
  • Infinite energy
  • The maximum energy
  • The minimum energy
  • Zero energy
The ratio of the kinetic energy to the total energy of an electron in a Bohr orbit is
  • –1
  • 2
  • 1 : 2
  • None of these
If an electron jumps from 1st orbital to 3rd orbital, then it will
  • Absorb energy
  • Release energy
  • No gain of energy
  • None of the above
The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is
  • 27 : 5
  • 5 : 27
  • 4 : 1
  • 1 : 4
In terms of Rydberg\'s constant R, the wave number of the first Balmer line is
  • R
  • 3R

  • Physics-Atoms and Nuclei-62773.png

  • Physics-Atoms and Nuclei-62774.png
If the ionisation potential of helium atom is 24.6 volt, the energy required to ionise it will be
  • 24.6 eV
  • 24.6 V
  • 13.6 V
  • 13.6 eV
Which of the transitions in hydrogen atom emits a photon of lowest frequency (n = quantum number)?
  • n = 2 to n = 1
  • n = 4 to n = 3
  • n = 3 to n = 1
  • n = 4 to n = 2
In a hydrogen atom, which of the following electronic transitions would involve the maximum energy change
  • From n = 2 to n = 1
  • From n = 3 to n = 1
  • From n = 4 to n = 2
  • From n = 3 to n = 2
In the lowest energy level of hydrogen atom, the electron has the angular momentum
  • π/h
  • h/π
  • h/2π
  • 2π/h
The minimum energy required to excite a hydrogen atom from its ground state is
  • 13.6 eV
  • –13.6 eV
  • 3.4 eV
  • 10.2 eV
Ratio of the wavelengths of first line of Lyman series and first line of Balmer series is
  • 1 : 3
  • 27 : 5
  • 5 : 27
  • 4 : 9
0:0:1


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