# Solved papers for NEET Physics Atomic Physics NEET PYQ-Atomic Physics

### done NEET PYQ-Atomic Physics Total Questions - 41

• question_answer1) Ratio of longest wavelengths corresponding to Lyman and Bulmer series in hydrogen spectrum is           [NEET 2013]

A)
$\frac{5}{27}$

B)
$\frac{3}{23}$

C)
$\frac{7}{29}$

D)
$\frac{9}{31}$

• question_answer2) The 21 cm radio wave emitted by hydrogen in interstellar space is due to the interaction called the hyperfine interaction in atomic hydrogen. The energy of the emitted wave is nearly:                                                                        [AIPMT 1998]

A)
${{10}^{-17}}\,J$

B)
1 J

C)
$7\times {{10}^{-6}}\,J$

D)

${{10}^{-24}}\,J$

• question_answer3) In the Bohr's model of a hydrogen atom, the centripetal force is furnished by the Coulomb attraction between the proton and the electron. If ${{a}_{0}}$ is the radius of the ground state orbit, m is the mass and e is the charge on the electron, ${{\varepsilon }_{0}}$ is the vacuum permittivity, the speed of the electron is :                  [AIPMT 1998]

A)
zero

B)
$\frac{e}{\sqrt{{{\varepsilon }_{0}}{{a}_{0}}m}}$

C)
$\frac{e}{\sqrt{4\pi {{\varepsilon }_{0}}{{a}_{0}}m}}$

D)
$\frac{\sqrt{4\pi {{\varepsilon }_{0}}{{a}_{0}}m}}{e}$

• question_answer4) The resistance of a discharge tube is:                                                                     [AIPMT 1999]

A)
zero

B)
ohmic

C)
non-ohmic

D)
infinity

• question_answer5) When electron jumps from $n=4$ to $n=2$ orbit, we get:                                     [AIPMT 2000]

A)
second line of Lyman series

B)
second line of Balmer series

C)
second line of Paschen series

D)
an absorption line of Balmer series

• question_answer6) Which of the following transitions gives photon of maximum energy?                        [AIPMT 2000]

A)
$n=1$ to $n=2$

B)
$n=2$ to $n=1$

C)
$n=2$ to $n=6$

D)
$n=6$ to $n=2$

• question_answer7) The energy of a photon of light is 3 eV. Then the wavelength of photon must be:                     [AIPMT 2000]

A)
4125 nm

B)
412.5 nm

C)
41250 nm

D)
4 nm

• question_answer8) The value of Planck's constant is:                                                                                      [AIPMT 2002]

A)

$6.63\times {{10}^{-34}}\,J/s$

B)
$6.63\times {{10}^{-34}}\,kg-m/s$

C)
$6.63\times {{10}^{-34}}\,kg-{{m}^{2}}$

D)
$6.63\times {{10}^{-34}}\,J-s$

• question_answer9) Which of the following is not the property of cathode rays?                         [AIPMT 2002]

A)
It produces heating effect

B)
It does not deflect in electric field

C)

D)
It produces fluorescence

• question_answer10) J.J. Thomson's cathode-ray tube experiment demonstrated that:                  [AIPMT 2003]

A)
the e/m of electrons is greater than the e/m of protons

B)
the e/m ratio of the cathode-ray particles changes when a different gas is placed in the discharge tube

C)
cathode rays axe streams of negatively charged ions

D)
all the mass of an atom is essentially in the nucleus

• question_answer11) In which of the following systems will the radius of the first orbit $(n=1)$ be minimum?                       [AIPMT 2003]

A)
Deuterium atom

B)
Hydrogen atom

C)
Doubly ionized lithium

D)
Singly ionized helium

• question_answer12) The mass number of a nucleus is:                                                              [AIPMT 2003]

A)
sometimes equal to its atomic number

B)
sometimes less than and sometimes more than its atomic number

C)
always less than its atomic number

D)
always more than its atomic number

• question_answer13) A nucleus represented by the symbol $_{Z}^{A}X$has:                                                    [AIPMT (S) 2004]

A)
Z neutrons and A -Z protons

B)
Z protons and A-Z neutrons

C)
Z protons and A neutrons

D)
A protons and Z-A neutrons

• question_answer14) The Bohr model of atoms:

A)
assumes that the angular momentum of electrons is quantized  B)       uses Einstein's photoelectric equation C)       predicts continuous emission spectra for atoms D)       predicts the same emission spectra for all types of atoms View Answer play_arrow question_answer15) Energy E of a hydrogen atom with principal quantum number n is given by $E=\frac{-13.6}{{{n}^{2}}}eV$. The energy of a photon ejected when the electron jumps from $n=3$ state to $n=2$ state of hydrogen, is approximately:                                                                                                                                      [AIPMT (S) 2004] A)  1.5 eV              B)       0.85 eV C) 3.4 eV  D)  1.9 eV View Answer play_arrow question_answer16) Energy levels A, B and C of a certain atom correspond to increasing values of energy i.e., ${{E}_{A}}<{{E}_{B}}<{{E}_{C}}$. If ${{\lambda }_{1}},\,{{\lambda }_{2}}$ and ${{\lambda }_{3}}$ are wavelengths of radiations corresponding to transitions C to B, B to A and C to A respectively, which of the following relations is correct?                                                                                                 [AIPMT (S) 2005] A)  ${{\lambda }_{3}}={{\lambda }_{1}}+{{\lambda }_{2}}$      B)      ${{\lambda }_{3}}=\frac{{{\lambda }_{1}}{{\lambda }_{2}}}{{{\lambda }_{1}}+{{\lambda }_{2}}}$ C)  ${{\lambda }_{1}}+{{\lambda }_{2}}+{{\lambda }_{3}}=0$ D)       $\lambda _{3}^{2}=\lambda _{1}^{2}+\lambda _{2}^{2}$ View Answer play_arrow question_answer17) The nuclei of which one of the following pairs of nuclei are isotones?     [AIPMT (S) 2005] A)  $_{34}S{{e}^{74}},{{\,}_{31}}G{{a}^{71}}$         B)  $_{42}M{{o}^{92}}\,,{{\,}_{40}}Z{{r}^{92}}$ C)  $_{38}S{{r}^{84}},{{\,}_{38}}S{{r}^{86}}$           D)  $_{20}C{{a}^{40}},\,{{\,}_{16}}{{S}^{32}}$ View Answer play_arrow question_answer18) The total energy of an electron in the first excited state of hydrogen is about $-3.4\text{ }eV$. Its kinetic energy in this state is:                                                                                                           [AIPMT (S) 2005] A)  $-3.4\text{ }eV$ B)                   $-6.8\,eV$ C)  $6.8\text{ }eV$   D)             $3.4\text{ }eV$

• question_answer19) Ionization 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:     [AIPMT (S) 2006]

A)
two

B)
three

C)
four

D)
one

• question_answer20) In a discharge tube ionization of enclosed gas is produced due to collisions between:                 [AIPMT (S) 2006]

A)
positive ions and neutral atoms/molecules

B)
negative electrons and neutral atoms/molecules

C)
photons and neutral atoms/molecules

D)
neutral gas atoms/molecules

• question_answer21) The total energy of electron in the ground state of hydrogen atom is $-13.6\text{ }eV$. The kinetic energy of an electron in the first excited state is:                                                                                             [AIPMT (S) 2007]

A)
3.4 eV

B)
6.8 eV

C)
13.6 eV

D)
1.7 eV

• question_answer22) The work function of a surface of a photosensitive material is 6.2 eV. The wavelength, of the incident radiation for which the stopping potential is 5 V lies in the                                                               [AIPMPT (S) 2008]

A)
ultraviolet region

B)
visible region

C)
infrared region

D)
X-ray region

• question_answer23)  A particle shows distance-time curve as given in this figure. The maximum instantaneous velocity of the particle is around the point                                                                                         [AIPMPT (S) 2008]

A)
B

B)
C

C)
D

D)
A

• question_answer24) An alpha nucleus of energy $\frac{1}{2}m{{v}^{2}}$ bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to

A)
$\frac{1}{Ze}$

B)
${{v}^{2}}$

C)
$\frac{1}{m}$

D)
$\frac{1}{{{v}^{4}}}$

• question_answer25) The electron in the hydrogen atom jumps from excited state $(n=3)$ to its ground state $(n=1)$ and the photons thus emitted irradiate a photosensitive material. If the work function of the material is 5.1 eV, the stopping potential is estimated to be (the energy of the electron in nth state ${{E}_{n}}=-\frac{13.6}{{{n}^{2}}}eV$)           [AIPMT (M) 2010]

A)
5.1 V

B)
12.1 V

C)
17.2 V

D)
7 V

• question_answer26) Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?                                                                                                              [AIPMT (M) 2011]

A)
1.9 eV

B)
11.1 eV

C)
13.6 eV

D)
0.65 eV

• question_answer27) The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number Z of hydrogen like ion is                                             [AIPMT (S) 2011]

A)
4

B)
1

C)
2

D)
3

• question_answer28)                  The transition from the state $n=3$ to $n=1$ in a hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from                                                                              [AIPMT (M) 2012]

A)
$2\to 1$

B)
$3\to 2$

C)
$4\to 2$

D)
$4\to 3$

• question_answer29) Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelengths ${{\lambda }_{1}}:{{\lambda }_{2}}$ emitted in the two cases is                                                                                                                                         [AIPMT (S) 2012]

A)
7/5

B)
27/20

C)
27/5

D)
20/7

• question_answer30) An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be                                                                    [AIPMT (S) 2012]

A)
$\frac{24\,hR}{25\,m}$

B)
$\frac{25\,hR}{24\,m}$

C)
$\frac{25\,m}{24\,h\,R}$

D)
$\frac{24\,m}{25\,h\,R}$

• question_answer31) Hydrogen atom in ground state is excited by a monochromatic   radiation   of $\lambda =975\,\overset{o}{\mathop{A}}\,$. Number of spectral lines in the resulting spectrum emitted will be                                           [NEET 2014]

A)
3

B)
2

C)
6

D)
10

• question_answer32) Consider ${{3}^{rd}}$ orbit of $H{{e}^{+}}$ (Helium), using non-relativistic approach, the speed of electron in this orbit will be (given $K=9\times {{10}^{9}}$ constant, $Z=2$and h (Planck's constant) $=6.6\times {{10}^{-34}}J-s$) [NEET  2015]

A)
$2.92\times {{10}^{6}}m/s$

B)
$1.46\times {{10}^{6}}m/s$

C)
$0.73\times {{10}^{6}}m/s$

D)
$3.0\times {{10}^{8}}m/s$

• question_answer33) In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is                                                                                                              [NEET (Re) 2015]

A)
$\frac{4}{9}$

B)
$\frac{9}{4}$

C)
$\frac{27}{5}$

D)
$\frac{5}{27}$

• question_answer34) An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is :          [NEET - 2016]

A)
$\frac{1}{c}{{\left( \frac{E}{2m} \right)}^{\frac{1}{2}}}$

B)
${{\left( \frac{E}{2m} \right)}^{\frac{1}{2}}}$

C)
$c{{\left( 2mE \right)}^{\frac{1}{2}}}$

D)
$\frac{1}{xc}{{\left( \frac{2m}{E} \right)}^{\frac{1}{2}}}$ (c being velocity of light)

• question_answer35) When an $\alpha -$particle of mass 'm' moving with velocity $'v'$ bombards on a heavy nucleus of charge $'Ze'$, its distance of closest approach from the nucleus depends on m as :                                                        [NEET - 2016]

A)
$\frac{1}{m}$

B)
$\frac{1}{\sqrt{m}}$

C)
$\frac{1}{{{m}^{2}}}$

D)
m

• question_answer36) Given the value of Rydberg constant is ${{10}^{7}}{{m}^{-1}},$ the wave number of the last line of the Balmer series in hydrogen spectrum will be :-                                                                     [NEET - 2016]

A)
$0.025\times {{10}^{4}}\text{ }{{m}^{1}}$

B)
$0.5\times {{10}^{7}}\text{ }{{m}^{1}}$

C)
$0.25\times {{10}^{7}}\text{ }{{m}^{1}}$

D)
$2.5\times {{10}^{7}}\text{ }{{m}^{1}}$

• question_answer37) The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is                  [NEET-2017]

A)
0.5

B)
2

C)
1

D)
4
[d] For last Balmer series

• question_answer38) The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is      [NEET - 2018]

A)
2 : -1

B)
1 : - 1

C)
1 : 1

D)
1 : - 2

• question_answer39) $\alpha$-particle consists of:                                                                                [NEET 2019]

A)
2 electrons and 4 protons only

B)
2 protons only

C)
2 protons and 2 neutrons only

D)
2 electrons, 2 protons and 2 neutrons

• question_answer40) The total energy of an electron in an atom in an orbit is -3.4 eV. Its kinetic and potential energies are, respectively-                                                                                                                                 [NEET 2019]

A)
3.4 eV, - 6.8 eV

B)
3.4 eV, 3.4 eV

C)
- 3.4 eV, - 3.4 eV

D)
- 3.4 eV, - 6.8 eV

• question_answer41) For which one of the following, Bohr model is not valid ?                                         [NEET 2020]

A)
Singly ionised helium atom $\left( H{{e}^{+}} \right)$

B)
Deuteron atom

C)
Singly ionised neon atom $\left( N{{e}^{+}} \right)$

D)
Hydrogen atom