JEE Questions for Physics Atoms And Nuclei Quiz 1 - MCQExams.com

For ionising an excited hydrogen atom, the energy required (in eV) will be
  • a little less than 13.6
  • 13.6
  • more than 13.6
  • 3.4 or less

Physics-Atoms and Nuclei-62582.png
  • 73
  • 74
  • 75
  • 72
Mass of the nucleons together in a heavy nucleus is
  • greater than mass of nucleus
  • equal to mass of nucleus
  • same as mass of nucleus
  • None of the above
Which one of the following statement is true, if half-life of a radioactive substance is I month?
  • 7/8th part of the substance will disintegrate in 3 months
  • 1/8th part of the substance will remain undecayed at the end of 4 months
  • The substance will disintegrate completely in 4 months
  • 1.16th part of the substance will remain undecayed at the end of 3 months
  • The substance will disintegrate completely in 2 months.
If λ is decay constant and N the number of radioactive nuclei of an element, then the decay rate (R) of that element is
  • λN2
  • λN
  • λ/N
  • λ2 N
What is the maximum wavelength of light emitted in Lyman series by hydrogen atom?
  • 691 nm
  • 550 nm
  • 380 nm
  • 122 nm
In a radioactive decay. The half - life of radioactive substance is T1/2 = 69.3s. the decay constant is
  • 1.5 s-1
  • 2.21 s-1
  • 0.01 s-1
  • 3.01 s-1
The α-particle is the nucleus of an atom of
  • Neon
  • Hydrogen
  • Helium
  • Deuterium
Which of the following value is the correct order of nuclear density?
  • 5 × 105 kg/m3
  • 9 × 1010 kg/m3
  • 3 × 1021 kg/m3
  • 2 × 1017 kg/m3
The nucleus of an atom consists of
  • electrons and protons
  • electrons, protons and neutrons
  • electrons and neutrons
  • neutrons and protons
In Rutherford scattering experiment, what will be the correct angle for a scattering for an impact parameter b = 0?
  • 90o
  • 270o
  • 0o
  • 180o
In hydrogen atom, an electron jumps from bigger orbit to smaller orbit so that radius of smaller orbit is one-fourth of radius of bigger orbit. If speed of electron is bigger orbit was v, then speed in smaller orbit is
  • v/4
  • v/2
  • v
  • 2v
If the electron in the hydrogen atom jumps from third orbit to second orbit the wavelength of the emitted radiation in term of Rydberg constant is
  • 6/5R
  • 36/5R
  • 64/7R
  • None of these
The ratio of the wavelength for 2 → 1 transition in Li++, He+ and H is
  • 1 : 2 : 3
  • 1 : 4 : 9
  • 4 : 9 : 36
  • 3 : 2 : 1
If the ratio of radii of two spheres of same material is 1 : 4, then the ratio of their heat capacities is
  • 1/64
  • 1/32
  • 1/16
  • 1/4
The ratio of radii of the nuclei, 13 Al27 and 52Te125 is
  • 13 : 52
  • 27 : 125
  • 3 : 5
  • 14 : 73
Assume that a neutron breaks into a proton and an electron. The energy released during this process is (Mass of neutron =1.6725 × 10-27 kg, mass of electron = 9 × 10-31 kg,)
  • 0.9 MeV
  • 7.10 MeV
  • 6.30 MeV
  • 5.4 MeV

Physics-Atoms and Nuclei-62417.png

  • Physics-Atoms and Nuclei-62418.png
  • 2)
    Physics-Atoms and Nuclei-62419.png

  • Physics-Atoms and Nuclei-62420.png

  • Physics-Atoms and Nuclei-62421.png
Calculate the highest frequency of the emitted photon in the paschen series of spectral lines of the hydrogen atom
  • 3.7 × 1014 Hz
  • 9.1 × 1015 Hz
  • 10.23 × 1014 Hz
  • 29.7 × 1015 Hz
α – particles of kinetic energy 7.7 MeV are being scattered by the nucleus of gold which has 79 electrons. The distance of closest approach of the alpha particles is
Physics-Atoms and Nuclei-62422.png
  • 4 × 10-14 m
  • 30 × 10-15 m
  • 10 × 10-15 m
  • 7.9 × 10-14 m
The orbital frequency of an electron in the hydrogen atom is proportional to
  • n3
  • n-3
  • n
  • no
The product of linear momentum and angular momentum of an electron of the hydrogen atom is proportional to nx, where x is
  • 0
  • 1
  • –2
  • 2
Which of the following transitions in Balmer series for hydrogen will have longest wavelength?
  • n = 2 to n = 1
  • n = 6 to n = 1
  • n = 3 to n = 2
  • n = 6 to n = 2
Ionisation energy of He+ ion at minimum position is
  • 13.6 eV
  • 27.2 eV
  • 54.4 eV
  • 68.0 eV
Which of the following transition gives the photon of minimum frequency?
  • n = 2 to n = 1
  • n = 3 to n = 1
  • n = 3 to n = 2
  • n = 4 to n = 3
According to Bohr's theory of hydrogen atom, for the electron in the nth allowed orbit the
I. . linear momentum is proportional to 1/n
II. radius is proportional to n
III. kinetic energy is proportional to 1/n2
IV. angular momentum is proportional to n
Choose the correct option from the codes given below.
  • I, III, IV are correct
  • Only I is correct
  • I and II are correct
  • Only III is correct
The radius of hydrogen atom in its ground state is 5.3 × 10-11 m. After collision with an electron it is found to have a radius of 21.2 × 10-11 m. What is the principal quantum number n of the final state of atom ?
  • n = 4
  • n = 2
  • n = 16
  • n = 3
If an electron is revolving around the hydrogen nucleus at a distance of 0.1 nm, what should be its speed?
  • 2.188 × 106 ms-1
  • 1.094 × 106 ms-1
  • 4.376 × 106 ms-1
  • 1.59 × 106 ms-1
Continuous emission spectrum is produced by
  • incandescent electric lamp
  • mercury vapour lamp
  • sodium vapour lamp
  • polyatomic substances
The ratio of areas of the electron orbits for the first excited state and the ground state for the hydrogen atom is
  • 4 : 1
  • 16 : 1
  • 8 : 1
  • 2 : 1
Which of the following lines of the H–atom spectrum belongs to the Balmer series?
  • 1025 Å
  • 1218 Å
  • 3646 Å
  • 18751 Å
The ratio of kinetic energy and the total energy of the electron in the nth quantum state of Bohr's atomic model of hydrogen atom is
  • -2
  • -1
  • +2
  • +1
The first excitation potential of a given atom is 10.2 V. Then, ionisation potential must be
  • 20.4 V
  • 13.6 V
  • 30.6 V
  • 40.8 V
The ratio of minimum to maximum wavelength in Balmer series is
  • 5 : 9
  • 5 : 36
  • 1 : 4
  • 3 : 4
The ground state energy of hydrogen atom is i 3.6 eV. When its electron is in the first excited state, its excitation energy is
  • 3.4 eV
  • 6.8 eV
  • 10.2 eV
  • Zero
Solar spectrum is an example for
  • line emission spectrum
  • continuous emission spectrum
  • band absorption spectrum
  • line absorption spectrum
In the Bohr model of hydrogen atom, the electron is pictured to rotate in a circular orbit of radius 5 × 10-11 m, at a speed 2.2 × 106 ms-1 . What is the current associated with electron motion?
  • 1.12 mA
  • 3 mA
  • 0.75 mA
  • 2.25 mA
The ionisation potential of hydrogen atom is –13.6 eV. An electron in the ground state of a hydrogen atoms absorbs a photon of energy 1275 eV. How many different spectral line can one expect when the electron make a downward transition?
  • 1
  • 4
  • 2
  • 6
First Bohr radius of an atom with Z = 82 is R. Radius of its third orbit is
  • 9R
  • 6R
  • 3R
  • R
The magnetic moment of the ground state of an atom whose open sub-shell is half-filled with five electrons is
  • √35√μb
  • 35 μB
  • 35 √μB
  • μB √35
Assuming f to be frequency of first line in Balmer series, the frequency of the immediate next (i.e. second) line is
  • 0.50f
  • 1.35f
  • 2.05f
  • 2.70f
Ionisation potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be
  • two
  • three
  • four
  • one
If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of Li2+ is
  • 30.6 eV
  • 13.6 eV
  • 3.4 eV
  • 122.4 eV
Electrons in a certain energy level n = n1, can emit 3 spectral lines. When they arc in another energy level, n = n2 they can emit 6 spectral lines. The orbital speed of the electrons in the orbits are in the ratio
  • 4 : 3
  • 3 : 4
  • 2 : 1
  • 1 : 2
Three photons coming from excited atomic hydrogen sample are observed, their energies arc 12.1 eV, 10.2 eV and 1.9 eV. These photons must come from
  • single atom
  • two atoms
  • three atoms
  • Either two or three atoms

Physics-Atoms and Nuclei-62431.png
  • 1 - C, 2 - A, 3 - B, 4 - D
  • 1 - C, 2 - B, 3 - A, 4 - D
  • 1 - B, 2 - C, 3 - A, 4 - D
  • 1 - B, 2- A, 3 - C, 4 - D
The Kα line of singly ionised calcium has a wavelength of 393.3 nm as measured on earth. In the spectrum of one of the observed galaxies, the spectral line is located at 401.8 nm. The speed with which this galaxy is moving away from us, will be
  • 7400 ms-1
  • 3.24 × 102 ms-1
  • 6480 kms-1
  • None of these
The wavelength of the first spectral line of sodium is 5896 A. The first excitation potential of sodium atom will be (h = 6.63 × 10-34 Js)
  • 4.2 V
  • 3.5 V
  • 2.1 V
  • None of these
At the time of total solar eclipse, the spectrum of solar radiation will have
  • a large number of dark Fraunhofer lines
  • a smaller number of dark Fraunhofer lines
  • no lines at all
  • all Fraunhofer lines changed into bright coloured lines
Which state of triply ionised beryllium (Be3+) has the same orbital radius as that of the ground state of hydrogen?
  • n = 3
  • n = 4
  • n = 1
  • n = 2
0:0:1


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