JEE Main & Advanced Chemistry Structure of Atom / परमाणु संरचना Question Bank

done Atomic models and Planck's quantum theory Total Questions - 81

• question_answer1)
  Rutherford's experiment on scattering of particles showed for the first time that the atom has [IIT 1981; NCERT 1981; CMC Vellore 1991; CPMT 1984; Kurukshetra CEE 1998]
  A)
                  Electrons             done clear
  B)
                  Protons done clear
  C)
                  Nucleus                done clear
  D)
                  Neutrons done clear
  View Solution play_arrow

• question_answer2)
  Rutherford's scattering experiment is related to the size of the [IIT 1983; MADT Bihar 1995; BHU 1995]
  A)
                  Nucleus                done clear
  B)
                  Atom done clear
  C)
                  Electron               done clear
  D)
                  Neutron done clear
  View Solution play_arrow

• question_answer3)
  Rutherford's alpha particle scattering experiment eventually led to the conclusion that  [IIT 1986; RPMT 2002]
  A)
                  Mass and energy are related done clear
  B)
                  Electrons occupy space around the nucleus done clear
  C)
                  Neutrons are buried deep in the nucleus done clear
  D)
                  The point of impact with matter can be precisely determined done clear
  View Solution play_arrow

• question_answer4)
  Bohr's model can explain              [IIT 1985]
  A)
                  The spectrum of hydrogen atom only done clear
  B)
                  Spectrum of atom or ion containing one electron only done clear
  C)
                  The spectrum of hydrogen molecule done clear
  D)
                  The solar spectrum done clear
  View Solution play_arrow

• question_answer5)
  When atoms are bombarded with alpha particles, only a few in million suffer deflection, others pass out undeflected. This is because           [MNR 1979; NCERT 1980; AFMC 1995]
  A)
                  The force of repulsion on the moving alpha particle is small done clear
  B)
                  The force of attraction on the alpha particle to the oppositely charged electrons is very small done clear
  C)
                  There is only one nucleus and large number of electrons done clear
  D)
                  The nucleus occupies much smaller volume compared to the volume of the atom done clear
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• question_answer6)
  Positronium consists of an electron and a positron (a particle which has the same mass as an electron, but opposite charge) orbiting round their common centre of mass. Calculate the value of the Rydberg constant for this system.          
  A)
                  \[{{R}_{\infty }}/4\]         done clear
  B)
                  \[{{R}_{\infty }}/2\] done clear
  C)
                  \[2{{R}_{\infty }}\]           done clear
  D)
                  \[{{R}_{\infty }}\]             done clear
  View Solution play_arrow

• question_answer7)
  When \[\alpha \]-particles are sent through a thin metal foil, most of them go straight through the foil because (one or more are correct)                                            [IIT 1984]
  A)
                  Alpha particles are much heavier than electrons done clear
  B)
                  Alpha particles are positively charged done clear
  C)
                  Most part of the atom is empty space done clear
  D)
                  Alpha particles move with high velocity done clear
  View Solution play_arrow

• question_answer8)
  When an electron jumps from \[L\] to \[K\] shell              [CPMT 1983]
  A)
                  Energy is absorbed done clear
  B)
                  Energy is released done clear
  C)
                  Energy is sometimes absorbed and sometimes  released done clear
  D)
                  Energy is neither absorbed nor released done clear
  View Solution play_arrow

• question_answer9)
  When beryllium is bombarded with \[\alpha \]-particles, extremely penetrating radiations which cannot be deflected by electrical or magnetic field are given out. These are [CPMT 1983]
  A)
                  A beam of protons          done clear
  B)
                  \[\alpha \]-rays done clear
  C)
                  A beam of neutrons       done clear
  D)
                  X-rays done clear
  View Solution play_arrow

• question_answer10)
  Which one of the following is not the characteristic of Planck's quantum theory of radiation         [AIIMS 1991]
  A)
                  The energy is not absorbed or emitted in whole number or multiple of quantum done clear
  B)
                  Radiation is associated with energy done clear
  C)
                  Radiation energy is not emitted or absorbed conti- nuously but in the form of small packets called quanta done clear
  D)
                  This magnitude of energy associated with a quantum is proportional to the frequency done clear
  View Solution play_arrow

• question_answer11)
  The spectrum of \[He\] is expected to be similar to [AIIMS 1980, 91; DPMT 1983; MP PMT 2002]
  A)
                  \[H\]      done clear
  B)
                  \[L{{i}^{+}}\] done clear
  C)
                  \[Na\]   done clear
  D)
                  \[H{{e}^{+}}\] done clear
  View Solution play_arrow

• question_answer12)
  Energy of orbit                                  [DPMT 1984, 91]
  A)
                  Increases as we move away from nucleus done clear
  B)
                  Decreases as we move away from nucleus done clear
  C)
                  Remains same as we move away from nucleus done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer13)
  Bohr model of an atom could not account for
  A)
                  Emission spectrum done clear
  B)
                  Absorption spectrum done clear
  C)
                  Line spectrum of hydrogen done clear
  D)
                  Fine spectrum done clear
  View Solution play_arrow

• question_answer14)
  Existence of positively charged nucleus was established by [CBSE PMT 1991]
  A)
                  Positive ray analysis done clear
  B)
                  \[\alpha \]-ray scattering experiments done clear
  C)
                  X-ray analysis done clear
  D)
                  Discharge tube experiments done clear
  View Solution play_arrow

• question_answer15)
  Electron occupies the available orbital singly before pairing in any one orbital occurs, it is               [CBSE PMT 1991]
  A)
                  Pauli's exclusion principle done clear
  B)
                  Hund's Rule done clear
  C)
                  Heisenberg's principle done clear
  D)
                  Prout's hypothesis done clear
  View Solution play_arrow

• question_answer16)
  The wavelength of a spectral line for an electronic transition is inversely related to           [IIT 1988]
  A)
                  The number of electrons undergoing the transition done clear
  B)
                  The nuclear charge of the atom done clear
  C)
                  The difference in the energy of the energy levels involved in the transition done clear
  D)
                  The velocity of the electron undergoing the transition done clear
  View Solution play_arrow

• question_answer17)
  When an electron drops from a higher energy level to a low energy level, then  [AMU 1985]
  A)
                  Energy is emitted done clear
  B)
                  Energy is absorbed done clear
  C)
                  Atomic number increases done clear
  D)
                  Atomic number decreases done clear
  View Solution play_arrow

• question_answer18)
  Davisson and Germer's experiment showed that [MADT Bihar 1983]
  A)
                  \[\beta \]-particles are electrons done clear
  B)
                  Electrons come from nucleus done clear
  C)
                  Electrons show wave nature done clear
  D)
                  None of the above done clear
  View Solution play_arrow

• question_answer19)
  When an electron jumps from lower to higher orbit, its energy                                  [MADT Bihar 1982]
  A)
                  Increases             done clear
  B)
                  Decreases done clear
  C)
                  Remains the same           done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer20)
  Experimental evidence for the existence of the atomic nucleus comes from                                        [CBSE PMT 1989]
  A)
                  Millikan's oil drop experiment done clear
  B)
                  Atomic emission spectroscopy done clear
  C)
                  The magnetic bending of cathode rays done clear
  D)
                  Alpha scattering by a thin metal foil done clear
  View Solution play_arrow

• question_answer21)
  Which of the following statements does not form part of Bohr's model of the hydrogen atom    [CBSE PMT 1989]
  A)
                  Energy of the electrons in the orbit is quantized done clear
  B)
                  The electron in the orbit nearest the nucleus has the lowest energy done clear
  C)
                  Electrons revolve in different orbits around the nucleus done clear
  D)
                  The position and velocity of the electrons in the orbit cannot be determined simultaneously done clear
  View Solution play_arrow

• question_answer22)
  When \[\beta \]-particles are sent through a tin metal foil, most of them go straight through the foil as [EAMCET 1983]
  A)
                  \[\beta \]-particles are much heavier than electrons done clear
  B)
                  \[\beta \]-particles are positively charged done clear
  C)
                  Most part of the atom is empty space done clear
  D)
                  \[\beta \]-particles move with high velocity done clear
  View Solution play_arrow

• question_answer23)
  The energy of second Bohr orbit of the hydrogen atom is ?328 kJ mol?1, hence the energy of fourth Bohr orbit would be [CBSE PMT 2005]
  A)
                  ? 41 kJ mol?1       done clear
  B)
                  ?1312 kJ mol?1 done clear
  C)
                  ?164 kJ mol?1     done clear
  D)
                  ? 82 kJ mol?1 done clear
  View Solution play_arrow

• question_answer24)
  When an electron revolves in a stationary orbit then [MP PET 1994]
  A)
                  It absorbs energy done clear
  B)
                  It gains kinetic energy done clear
  C)
                  It emits radiation done clear
  D)
                  Its energy remains constant done clear
  View Solution play_arrow

• question_answer25)
  A moving particle may have wave motion, if
  A)
                  Its mass is very high done clear
  B)
                  Its velocity is negligible done clear
  C)
                  Its mass is negligible done clear
  D)
                  Its mass is very high and velocity is negligible done clear
  View Solution play_arrow

• question_answer26)
  The postulate of Bohr theory that electrons jump from one orbit to the other, rather than flow is according to
  A)
                  The quantisation concept done clear
  B)
                  The wave nature of electron done clear
  C)
                  The probability expression for electron done clear
  D)
                  Heisenberg uncertainty principle done clear
  View Solution play_arrow

• question_answer27)
  The frequency of an electromagnetic radiation is \[2\times {{10}^{6}}Hz\]. What is its wavelength in metres                 (Velocity of light \[=3\times {{10}^{8}}m{{s}^{-1}}\])
  A)
                  \[6.0\times {{10}^{14}}\]              done clear
  B)
                  \[1.5\times {{10}^{4}}\] done clear
  C)
                  \[1.5\times {{10}^{2}}\]                 done clear
  D)
                  \[0.66\times {{10}^{-2}}\] done clear
  View Solution play_arrow

• question_answer28)
  What is the packet of energy called         [AFMC 2005]
  A)
                  Electron               done clear
  B)
                  Photon done clear
  C)
                  Positron done clear
  D)
                  Proton done clear
  View Solution play_arrow

• question_answer29)
  The energy of an electron in \[{{n}^{th}}\] orbit of hydrogen atom is [MP PET 1999]
  A)
                  \[\frac{13.6}{{{n}^{4}}}eV\]         done clear
  B)
                  \[\frac{13.6}{{{n}^{3}}}eV\] done clear
  C)
                  \[\frac{13.6}{{{n}^{2}}}eV\]         done clear
  D)
                  \[\frac{13.6}{n}eV\] done clear
  View Solution play_arrow

• question_answer30)
  If wavelength of photon is\[{{X}^{3-}}\]\[h=6.6\times {{10}^{-34}}\]J-sec, then momentum of photon is               [MP PET 1999]
  A)
                  \[3\times {{10}^{-23}}kg\,m{{s}^{-1}}\] done clear
  B)
                  \[3.33\times {{10}^{22}}kg\,m{{s}^{-1}}\] done clear
  C)
                  \[1.452\times {{10}^{-44}}\,kg\,m{{s}^{-1}}\]      done clear
  D)
                  \[6.89\times {{10}^{43}}\,kg\,m{{s}^{-1}}\] done clear
  View Solution play_arrow

• question_answer31)
  The expression for Bohr's radius of an atom is [MP PMT 1999]
  A)
                  \[r=\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}m{{e}^{4}}{{z}^{2}}}\]  done clear
  B)
                  \[r=\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}m{{e}^{2}}z}\] done clear
  C)
                  \[r=\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}m{{e}^{2}}{{z}^{2}}}\] done clear
  D)
                  \[r=\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}{{m}^{2}}{{e}^{2}}{{z}^{2}}}\] done clear
  View Solution play_arrow

• question_answer32)
  The energy of an electron revolving in \[{{n}^{th}}\] Bohr's orbit of an atom is given by the expression   [MP PMT 1999]
  A)
                  \[{{E}_{n}}=-\frac{2{{\pi }^{2}}{{m}^{4}}{{e}^{2}}{{z}^{2}}}{{{n}^{2}}{{h}^{2}}}\] done clear
  B)
                  \[{{E}_{n}}=-\frac{2{{\pi }^{2}}m{{e}^{2}}{{z}^{2}}}{{{n}^{2}}{{h}^{2}}}\] done clear
  C)
                  \[{{E}_{n}}=-\frac{2{{\pi }^{2}}m{{e}^{4}}{{z}^{2}}}{{{n}^{2}}{{h}^{2}}}\]                done clear
  D)
                  \[{{E}_{n}}=-\frac{2\pi {{m}^{2}}{{e}^{2}}{{z}^{4}}}{{{n}^{2}}{{h}^{2}}}\] done clear
  View Solution play_arrow

• question_answer33)
  Who modified Bohr's theory by introducing elliptical orbits for electron path       [CBSE PMT 1999; AFMC 2003]
  A)
                  Hund     done clear
  B)
                  Thomson done clear
  C)
                  Rutherford         done clear
  D)
                  Sommerfield done clear
  View Solution play_arrow

• question_answer34)
  Bohr's radius can have   [DPMT 1996]
  A)
                  Discrete values done clear
  B)
                  \[+ve\]values done clear
  C)
                  \[-ve\]values     done clear
  D)
                  Fractional values done clear
  View Solution play_arrow

• question_answer35)
  The first use of quantum theory to explain the structure of atom was made by  [IIT 1997; CPMT 2001; J&K CET 2005]
  A)
                  Heisenberg         done clear
  B)
                  Bohr done clear
  C)
                  Planck   done clear
  D)
                  Einstein done clear
  View Solution play_arrow

• question_answer36)
  An electronic transition from 1s orbital of an atom causes [JIPMER 1997]
  A)
                  Absorption of energy done clear
  B)
                  Release of energy done clear
  C)
                  Both release or absorption of energy done clear
  D)
                  Unpredictable done clear
  View Solution play_arrow

• question_answer37)
  In an element going away from nucleus, the energy of particle                                  [RPMT 1997]
  A)
                  Decreases           done clear
  B)
                  Not changing done clear
  C)
                  Increases             done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer38)
  The \[\alpha \]-particle scattering experiment of Rutherford concluded that                                       [Orissa JEE 1997]
  A)
                  The nucleus is made up of protons and neutrons done clear
  B)
                  The number of electrons is exactly equal to number of protons in atom done clear
  C)
                  The positive charge of the atom is concentrated in a very small space done clear
  D)
                  Electrons occupy discrete energy levels    done clear
  View Solution play_arrow

• question_answer39)
  Wavelength associated with electron motion     [BHU 1998]
  A)
                  Increases with increase in speed of electron done clear
  B)
                  Remains same irrespective of speed of electron done clear
  C)
                  Decreases with increase in speed of \[{{e}^{-}}\] done clear
  D)
                  Is zero done clear
  View Solution play_arrow

• question_answer40)
  The element used by Rutherford in his famous scattering experiment was                                           [KCET 1998]
  A)
                  Gold      done clear
  B)
                  Tin done clear
  C)
                  Silver     done clear
  D)
                  Lead done clear
  View Solution play_arrow

• question_answer41)
  If electron falls from \[n=3\] to \[n=2\], then emitted energy is [AFMC 1997; MP PET 2003]
  A)
                  \[10.2eV\]           done clear
  B)
                  \[12.09eV\] done clear
  C)
                  \[1.9eV\]             done clear
  D)
                  \[0.65eV\] done clear
  View Solution play_arrow

• question_answer42)
  The radius of the nucleus is related to the mass number \[A\]  by                             [EAMCET 1998]
  A)
                  \[R={{R}_{o}}{{A}^{1/2}}\]           done clear
  B)
                  \[R={{R}_{o}}A\] done clear
  C)
                  \[R={{R}_{o}}{{A}^{2}}\]               done clear
  D)
                  \[R={{R}_{o}}{{A}^{1/3}}\]  done clear
  View Solution play_arrow

• question_answer43)
  The specific charge of proton is \[9.6\times {{10}^{6}}C\,k{{g}^{-1}}\] then for an a-particle it will be                                       [MH CET 1999]
  A)
                  \[38.4\times {{10}^{7}}C\,k{{g}^{-1}}\]   done clear
  B)
                  \[19.2\times {{10}^{7}}C\,k{{g}^{-1}}\] done clear
  C)
                  \[2.4\times {{10}^{7}}C\,k{{g}^{-1}}\]     done clear
  D)
                  \[4.8\times {{10}^{7}}C\,k{{g}^{-1}}\] done clear
  View Solution play_arrow

• question_answer44)
  In hydrogen spectrum the different lines of Lyman series are present is                                                [UPSEAT 1999]
  A)
                  UV field                done clear
  B)
                  IR field done clear
  C)
                  Visible field         done clear
  D)
                  Far IR field done clear
  View Solution play_arrow

• question_answer45)
  Which one of the following is considered as the main postulate of Bohr?s model of atom               [AMU 2000]
  A)
                  Protons are present in the nucleus done clear
  B)
                  Electrons are revolving around the nucleus done clear
  C)
                  Centrifugal force produced due to the revolving electrons balances the force of attraction between the electron and the protons done clear
  D)
                          Angular momentum of electron is an integral multiple of \[\frac{h}{2\pi }\] done clear
  View Solution play_arrow

• question_answer46)
  The electronic energy levels of the hydrogen atom in the Bohr?s theory are called            [AMU 2000]
  A)
                  Rydberg levels  done clear
  B)
                  Orbits done clear
  C)
                  Ground states   done clear
  D)
                  Orbitals done clear
  View Solution play_arrow

• question_answer47)
  The energy of a photon is calculated by                 [Pb. PMT 2000]
  A)
                  \[E=h\nu \]         done clear
  B)
                  \[h=E\nu \] done clear
  C)
                  \[h=\frac{E}{\nu }\]        done clear
  D)
                  \[E=\frac{h}{\nu }\] done clear
  View Solution play_arrow

• question_answer48)
  Visible range of hydrogen spectrum will contain the following series                                       [RPET 2000]
  A)
                  Pfund    done clear
  B)
                  Lyman done clear
  C)
                  Balmer done clear
  D)
                  Brackett done clear
  View Solution play_arrow

• question_answer49)
  Radius of the first Bohr's orbit of hydrogen atom is  [RPET 2000]
  A)
  \[1.06\,{AA}\] done clear
  B)
  \[0.22\,{AA}\] done clear
  C)
  \[0.28\,{AA}\] done clear
  D)
  \[0.53\,{AA}\] done clear
  View Solution play_arrow

• question_answer50)
  In Balmer series of hydrogen atom spectrum which electronic transition causes third line              [MP PMT 2000]
  A)
                  Fifth Bohr orbit to second one done clear
  B)
                  Fifth Bohr orbit to first one done clear
  C)
                  Fourth Bohr orbit to second one done clear
  D)
                  Fourth Bohr orbit to first one done clear
  View Solution play_arrow

• question_answer51)
  Energy of electron of hydrogen atom in second Bohr orbit is [MP PMT 2000]
  A)
                  \[-5.44\times {{10}^{-19}}J\]       done clear
  B)
                  \[-5.44\times {{10}^{-19}}\,kJ\] done clear
  C)
                  \[-5.44\times {{10}^{-19}}\,cal\]                done clear
  D)
                  \[-5.44\times {{10}^{-19}}\,eV\] done clear
  View Solution play_arrow

• question_answer52)
  If change in energy \[(\Delta E)=3\times {{10}^{-8}}J,\,\,h=6.64\times {{10}^{-34}}J\text{-}s\] and \[c=3\times {{10}^{8}}\,m/s,\] then wavelength of the light is [CBSE PMT 2000]
  A)
                  \[6.36\times {{10}^{3}}\text{{ }\!\!\mathrm{\AA}\!\!\text{ }}\] done clear
  B)
                  \[6.36\times {{10}^{5}}\text{{ }\!\!\mathrm{\AA}\!\!\text{ }}\] done clear
  C)
                  \[6.64\times {{10}^{-8}}\text{{ }\!\!\mathrm{\AA}\!\!\text{ }}\]                done clear
  D)
                  \[6.36\times {{10}^{18}}\text{{ }\!\!\mathrm{\AA}\!\!\text{ }}\] done clear
  View Solution play_arrow

• question_answer53)
  The radius of first Bohr?s orbit for hydrogen is \[0.53\,{AA}\] . The radius of third Bohr's orbit would be   [MP PMT 2001]
  A)
  \[0.79{AA}\] done clear
  B)
  \[1.59{AA}\] done clear
  C)
  \[3.18{AA}~~~\] done clear
  D)
  \[4.77{AA}\] done clear
  View Solution play_arrow

• question_answer54)
  Rutherford?s a-particle scattering experiment proved that atom has                                      [MP PMT 2001]
  A)
                  Electrons             done clear
  B)
                  Neutron done clear
  C)
                  Nucleus                done clear
  D)
                  Orbitals done clear
  View Solution play_arrow

• question_answer55)
  Wavelength of spectral line emitted is inversely proportional to                                [CPMT 2001]
  A)
                  Radius   done clear
  B)
                  Energy done clear
  C)
                  Velocity done clear
  D)
                  Quantum number done clear
  View Solution play_arrow

• question_answer56)
  The energy of a radiation of wavelength \[8000\,{AA}\] is \[{{E}_{1}}\]and energy of a radiation of wavelength \[16000\text{ }{AA}\]is \[{{E}_{2}}\]. What is the relation between these two               [Kerala CET 2005]
  A)
  \[{{E}_{1}}=6{{E}_{2}}\] done clear
  B)
  \[{{E}_{1}}=2{{E}_{2}}\] done clear
  C)
  \[{{E}_{1}}=4{{E}_{2}}\] done clear
  D)
  \[{{E}_{1}}=1/2{{E}_{2}}\] done clear
  E)
  \[{{E}_{1}}={{E}_{2}}\] done clear
  View Solution play_arrow

• question_answer57)
  The formation of energy bonds in solids are in accordance with                                                 [DCE 2001]
  A)
                  Heisenberg?s uncertainty principle done clear
  B)
                  Bohr?s theory done clear
  C)
                  Ohm?s law done clear
  D)
                  Rutherford?s atomic model done clear
  View Solution play_arrow

• question_answer58)
  The frequency of yellow light having wavelength 600 nm is          [MP PET 2002]
  A)
                  \[5.0\times {{10}^{14}}Hz\]         done clear
  B)
                  \[2.5\times {{10}^{7}}Hz\] done clear
  C)
                  \[5.0\times {{10}^{7}}Hz\]            done clear
  D)
                  \[2.5\times {{10}^{14}}Hz\] done clear
  View Solution play_arrow

• question_answer59)
  The value of the energy for the first excited state of hydrogen atom will be                                         [MP PET 2002]
  A)
                  \[-\,13.6\,eV\] done clear
  B)
                  \[-\,3.40\,eV\] done clear
  C)
                  \[-\,1.51\,eV\]  done clear
  D)
                  \[-\,0.85\,eV\] done clear
  View Solution play_arrow

• question_answer60)
  Bohr model of atom is contradicted by   [MP PMT 2002]
  A)
                  Pauli?s exclusion principle done clear
  B)
                  Planck quantum theory done clear
  C)
                  Heisenberg uncertainty principle done clear
  D)
                  All of these done clear
  View Solution play_arrow

• question_answer61)
  Which of the following is not true in Rutherford?s nuclear model of atom                                              [Orissa JEE 2002]
  A)
                  Protons and neutrons are present inside nucleus done clear
  B)
                  Volume of nucleus is very small as compared to volume of atom done clear
  C)
                  The number of protons and neutrons are always equal done clear
  D)
                  The number of electrons and protons are always equal done clear
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• question_answer62)
  The emission spectrum of hydrogen is found to satisfy the expression for the energy change. \[\Delta E\] (in joules) such that \[\Delta E=2.18\times 10\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right)\,\,J\] where \[{{n}_{1}}\] = 1, 2, 3?.. and \[{{n}_{2}}\] = 2, 3, 4??. The spectral lines correspond to Paschen series to                                         [UPSEAT 2002]
  A)
                  \[{{n}_{1}}=1\] and \[{{n}_{2}}=2,\,\,3,\,\,4\] done clear
  B)
                  \[{{n}_{1}}=3\] and \[{{n}_{2}}=4,\,\,5,\,\,6\] done clear
  C)
                  \[{{n}_{1}}=1\] and \[{{n}_{2}}=3,\,\,4,\,\,5\] done clear
  D)
                  \[{{n}_{1}}=2\] and \[{{n}_{2}}=3,\,\,3,\,\,5\] done clear
  E)
                  \[{{n}_{1}}=1\] and \[{{n}_{2}}=\text{infinity}\] done clear
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• question_answer63)
  The ratio between kinetic energy and the total energy of the electrons of hydrogen atom according to Bohr?s model is [Pb. PMT 2002]
  A)
                  2 : 1        done clear
  B)
                  1 : 1 done clear
  C)
                  1 : ? 1    done clear
  D)
                  1 : 2 done clear
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• question_answer64)
  Energy of the electron in Hydrogen atom is given by [AMU (Engg.) 2002]
  A)
                  \[{{E}_{n}}=-\frac{131.38}{{{n}^{2}}}\,kJ\,mo{{l}^{-1}}\] done clear
  B)
                  \[{{E}_{n}}=-\frac{131.33}{n}\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[{{E}_{n}}=-\frac{1313.3}{{{n}^{2}}}\,kJ\,mo{{l}^{-1}}\] done clear
  D)
                  \[{{E}_{n}}=-\frac{313.13}{{{n}^{2}}}\,kJ\,mo{{l}^{-1}}\] done clear
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• question_answer65)
  Ratio of radii of second and first Bohr orbits of H atom [BHU 2003]
  A)
                  2              done clear
  B)
                  4 done clear
  C)
                  3              done clear
  D)
                  5 done clear
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• question_answer66)
  The frequency corresponding to transition \[n=2\] to \[n=1\] in hydrogen atom is            [MP PET 2003]
  A)
                  \[15.66\times {{10}^{10}}Hz\]     done clear
  B)
                  \[24.66\times {{10}^{14}}Hz\] done clear
  C)
                  \[30.57\times {{10}^{14}}Hz\]     done clear
  D)
                  \[40.57\times {{10}^{24}}Hz\] done clear
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• question_answer67)
  The mass of a photon with a wavelength equal to \[1.54\times {{10}^{-8}}cm\] is                                              [Pb. PMT 2004]
  A)
                  \[0.8268\times {{10}^{-34}}kg\] done clear
  B)
                  \[1.2876\times {{10}^{-33}}kg\] done clear
  C)
                  \[1.4285\times {{10}^{-32}}kg\] done clear
  D)
                  \[1.8884\times {{10}^{-32}}kg\] done clear
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• question_answer68)
  Splitting of spectral lines under the influence of magnetic field is called                  [MP PET 2004]
  A)
                  Zeeman effect  done clear
  B)
                  Stark effect done clear
  C)
                  Photoelectric effect        done clear
  D)
                  None of these done clear
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• question_answer69)
  The radius of electron in the first excited state of hydrogen atom is                                         [MP PMT 2004]
  A)
                  \[{{a}_{0}}\]       done clear
  B)
                  \[4{{a}_{0}}\] done clear
  C)
                  \[2{{a}_{0}}\]     done clear
  D)
                  \[8{{a}_{0}}\] done clear
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• question_answer70)
  The ratio of area covered by second orbital to the first orbital is                                                 [AFMC 2004]
  A)
                  1 : 2        done clear
  B)
                  1 : 16 done clear
  C)
                  8 : 1        done clear
  D)
                  16 : 1 done clear
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• question_answer71)
  Time taken for an electron to complete one revolution in the Bohr orbit of hydrogen atom is      [Kerala PMT 2004]
  A)
                  \[\frac{4{{\pi }^{2}}m{{r}^{2}}}{nh}\]      done clear
  B)
                  \[\frac{nh}{4{{\pi }^{2}}mr}\] done clear
  C)
                  \[\frac{nh}{4{{\pi }^{2}}m{{r}^{2}}}\]      done clear
  D)
                  \[\frac{h}{2\pi mr}\] done clear
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• question_answer72)
  The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom [IIT Screening 2004]
  A)
                  \[H{{e}^{+}}(n=2)\]         done clear
  B)
                  \[L{{i}^{2+}}(n=2)\] done clear
  C)
                  \[L{{i}^{2+}}(n=3)\]         done clear
  D)
                  \[B{{e}^{3+}}(n=2)\] done clear
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• question_answer73)
  The frequency of radiation emitted when the electron falls from \[n=4\] to \[n=1\] in a hydrogen atom will be (Given ionization energy of H\[=2.18\times {{10}^{-18}}J\,\,\,\text{ato}{{\text{m}}^{-1}}\]and \[h=6.625\times {{10}^{-34}}Js\])                                                [CBSE PMT 2004]
  A)
                  \[3.08\times {{10}^{15}}{{s}^{-1}}\]         done clear
  B)
                  \[2.00\times {{10}^{15}}{{s}^{-1}}\] done clear
  C)
                  \[1.54\times {{10}^{15}}{{s}^{-1}}\]         done clear
  D)
                  \[1.03\times {{10}^{15}}{{s}^{-1}}\] done clear
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• question_answer74)
  The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant \[=\,1.097\,\times \,{{10}^{7}}{{m}^{-1}}\]) [AIEEE 2004]
  A)
                  406 nm done clear
  B)
                  192 nm done clear
  C)
                  91 nm    done clear
  D)
                  \[9.1\,\times \,{{10}^{-8}}\,\,nm\] done clear
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• question_answer75)
  In Bohr?s model, atomic radius of the first orbit is \[\gamma \], the radius of the 3rd orbit, is         [MP PET 1997; Pb. CET 2001]
  A)
                  \[\gamma /3\] done clear
  B)
                  \[\gamma \] done clear
  C)
                  \[3\gamma \]    done clear
  D)
                  \[9\gamma \] done clear
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• question_answer76)
  According to Bohr?s principle, the relation between principle quantum number \[(n)\] and radius of orbit is         [BHU 2004]
  A)
                  \[r\propto n\]   done clear
  B)
                  \[r\propto {{n}^{2}}\] done clear
  C)
                  \[r\propto \frac{1}{n}\] done clear
  D)
                  \[r\propto \frac{1}{{{n}^{2}}}\] done clear
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• question_answer77)
  The ionisation potential of a hydrogen atom is ?13.6 eV. What will be the energy of the atom corresponding to \[n=2\] [Pb. CET 2000]
  A)
                  ?3.4 eV                 done clear
  B)
                  ?6.8 eV done clear
  C)
                  ?1.7 eV done clear
  D)
                  ? 2.7 eV done clear
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• question_answer78)
  The energy of electron in hydrogen atom in its grounds state is ?13.6 eV. The energy of the level corresponding to the quantum number equal to 5 is   [Pb. CET 2002]
  A)
                  ?0.54 eV               done clear
  B)
                  ? 0.85 eV done clear
  C)
                  ? 0.64 eV              done clear
  D)
                  ? 0.40 eV done clear
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• question_answer79)
  The positive charge of an atom is              [AFMC 2002]
  A)
                  Spread all over the atom done clear
  B)
                  Distributed around the nucleus done clear
  C)
                  Concentrated at the nucleus done clear
  D)
                  All of these done clear
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• question_answer80)
  A metal surface is exposed to solar radiations     [DPMT 2005]
  A)
                  The emitted electrons have energy less than a maximum value of energy depending upon frequency of incident radiations done clear
  B)
                  The emitted electrons have energy less than maximum value of energy depending upon intensity of incident radiation done clear
  C)
                  The emitted electrons have zero energy done clear
  D)
                  The emitted electrons have energy equal to energy of photos of incident light done clear
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• question_answer81)
  Which of the following transitions have minimum wavelength                                    [DPMT 2005]
  A)
                  \[{{n}_{4}}\to {{n}_{1}}\]              done clear
  B)
                  \[{{n}_{2}}\to {{n}_{1}}\] done clear
  C)
                  \[{{n}_{4}}\to {{n}_{2}}\] done clear
  D)
                  \[{{n}_{3}}\to {{n}_{1}}\] done clear
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