← Back to Physics

Atoms and Nuclei

140 Questions
All Exams NEET AIIMS
2007 NEET MCQ
AIPMT 2007
The total energy of electron in the ground state of hydrogen atom is $-$ 13.6 eV. The kinetic energy of an electron in the first excited state is
A.
6.8 eV
B.
13.6 eV
C.
1.7 eV
D.
3.4 eV.
2006 NEET MCQ
AIPMT 2006
The radius of germanium (Ge) nuclide is measured to be twice the radius of ${}_4^9$Be. The number of nucleons in Ge are
A.
72
B.
73
C.
74
D.
75
2006 NEET MCQ
AIPMT 2006
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is $\lambda $, then
A.
R1 = R2
B.
R1 = R2e$-$$\lambda $(t1$-$t2)
C.
R1 = R2e$\lambda $(t1$-$t2)
D.
R1 = R2(t2/t1).
2006 NEET MCQ
AIPMT 2006
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 emited by hydrogen will be
A.
one
B.
two
C.
three
D.
four
2006 NEET MCQ
AIPMT 2006
The binding energy of deuteron is 2.2 MeV and that of ${}_2^4$He is 28 MeV. If two deuterons are fused to form one ${}_2^4$He then the energy released is
A.
30.2 MeV
B.
25.8 MeV
C.
23.6 MeV
D.
19.2 MeV
2005 NEET MCQ
AIPMT 2005
Which one of the following pairs of nuclei are isotones ?
A.
34Se74,  31Ga71
B.
38Sr84,  38Sr86
C.
42Mo92,   40Zr92
D.
20Ca40,  16S32
2005 NEET MCQ
AIPMT 2005
In any fission process the ratio
mass of fission products
mass of parent nucleus
 is
A.
equal to 1
B.
greater than 1
C.
less than 1
D.
depends on the mass of the parent nucleus.
2005 NEET MCQ
AIPMT 2005
In the reaction ${}_1^2$H + ${}_1^3$H $ \to $ ${}_2^4$He + ${}_0^1$n, if the binding
energies of ${}_1^2$ H, ${}_1^3$H and ${}_2^4$He are respectively a, b and c (in MeV),
then the energy (in MeV) released in this reaction is
A.
a + b + c
B.
a + b $-$ c
C.
c $-$ a $-$ b
D.
c + a $-$ b
2005 NEET MCQ
AIPMT 2005
Energy levels A, B and C of a certain atom corresponding to increasing values of energy i.e. EA < EB < EC. If $\lambda $1, $\lambda $2 and $\lambda $3 are wavelengths of radioations corresponding to transitions C to B, B to A and C to A respectively, which of the following relations is correct?
A.
${\lambda _3} = {\lambda _1} + {\lambda _2}$
B.
${\lambda _3} = {{{\lambda _1}{\lambda _2}} \over {{\lambda _1} + {\lambda _2}}}$
C.
${\lambda _1} + {\lambda _2} + {\lambda _3} = 0$
D.
${\lambda _3}^2 = {\lambda _1}^2 + {\lambda _2}^2$
2005 NEET MCQ
AIPMT 2005
Fission of nuclei is possible because the binding energy per nucleon in them
A.
increases with mass number at low mass numbers
B.
decreases with mass number at low mass numbers
C.
increases with mass number at high mass numbers
D.
decreases with mass number at high mass numbers.
2005 NEET MCQ
AIPMT 2005
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
A.
3.4 eV
B.
6.8 eV
C.
$-$ 3.4 eV
D.
$-$ 6.8 eV
2004 NEET MCQ
AIPMT 2004
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 fror atoms.
D.
Predicts the same emission spectra for all types of atoms.
2004 NEET MCQ
AIPMT 2004
If in a nuclear fusion process the masses of the fusing nuclei be m1 and m2 and the mass of the resultant nucleus be m3, then
A.
m3 = m1 + m2
B.
m3 = $\left| {{m_1} - {m_2}} \right|$
C.
m3 < (m1 + m2)
D.
m3 > (m1 + m2)
2004 NEET MCQ
AIPMT 2004
A nucleus represented by the symbol ${}_Z^AX$ has
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
2004 NEET MCQ
AIPMT 2004
If M(A; Z), Mp and Mn denote the masses of the nucleus ${}_Z^AX,$ proton and neutron respectively in units of u (1 u = 931.5 MeV/c2) and BE represents its bonding energy in MeV, then
A.
M(A, Z) = ZMp + (A $-$ Z)Mn $-$ BE
B.
M(A, Z) = ZMp + (A $-$ Z)Mn + BE/c2
C.
M(A, Z) = ZMp + (A $-$ Z)Mn $-$ BE/c2
D.
M(A, Z) = ZMp + (A $-$ Z)Mn + BE
2004 NEET MCQ
AIPMT 2004
The half life of radian is about 1600 years. Of 100 g of radium existing now, 25 g will remain unchanged after
A.
4800 years
B.
6400 years
C.
2400 years
D.
3200 years
2003 NEET MCQ
AIPMT 2003
In which of the following systems will the radius of the first orbit (n = 1) be minimum ?
A.
doubly ionized lithium
B.
singly ionized helium
C.
deuterium atom
D.
hydrogen atom
2003 NEET MCQ
AIPMT 2003
The mass of proton is 1.0073 u and that of neutron is 1.0087 u (u = atomic mass unit). The binding energy of ${}_2^4$ He is
(Given helium nucleus mass $ \approx $ 4.0015 u.)
A.
0.0305 J
B.
0.0305 erg
C.
28.4 MeV
D.
0.061 u
2003 NEET MCQ
AIPMT 2003
The mass number of a nucleus is
A.
always less than its atomic number
B.
always more than its atomic number
C.
sometimes equal to its atomic number
D.
sometimes less than and sometimes more than its atomic number
2003 NEET MCQ
AIPMT 2003
An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The Coulomb force $\overrightarrow F $ between the two is
A.
$K{{{e^2}} \over {{r^2}}}\widehat r$
B.
$ - K{{{e^2}} \over {{r^3}}}\widehat r$
C.
$K{{{e^2}} \over {{r^3}}}\widehat r$
D.
$ - K{{{e^2}} \over {{r^2}}}\widehat r$
2003 NEET MCQ
AIPMT 2003
Solar energy is mainly caused due to
A.
burning of hydrogen in the oxygen
B.
fission of uranium present in the Sun
C.
fusion of protons during synthesis of heavier elements
D.
gravitational contraction
2003 NEET MCQ
AIPMT 2003
A sample of radioactive element has a mass of 10 g at an instant t = 0. The approximate mass of this element in the sample after two mean lives is
A.
1.35 g
B.
2.50 g
C.
3.70 g
D.
6.30 g
2003 NEET MCQ
AIPMT 2003
A nuclear reaction given by

ZXA $ \to $ z+1YA + $-$1e0 + $\overline v $ represents
A.
$\beta $-decay
B.
$\gamma $-decay
C.
fusion
D.
fission
2003 NEET MCQ
AIPMT 2003
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about
A.
101
B.
105
C.
1010
D.
1015
2002 NEET MCQ
AIPMT 2002
A sample of radioactive element containing 4 $ \times $ 1016 active nuclei. Half life of element is 10 days, then number of decayed nuclei after 30 days
A.
0.5 $ \times $ 1016
B.
2 $ \times $ 1016
C.
3.5 $ \times $ 1016
D.
1 $ \times $ 1016
2002 NEET MCQ
AIPMT 2002
A deutron is bombarded on 8O16 nucleus then $\alpha $-particle is emitted. The product nucleus is
A.
7N13
B.
5B10
C.
4Be9
D.
7N14
2002 NEET MCQ
AIPMT 2002
Which of the following are suitable for the fusion process ?
A.
light nuclei
B.
heavy nuclei
C.
element lying in the middle of the periodic table
D.
middle elements, which are lying on binding energy curve.
2001 NEET MCQ
AIPMT 2001
Which rays contain (positive) charged particles ?
A.
$\alpha $-rays
B.
$\beta $-rays
C.
$\gamma $-rays
D.
X-rays
2001 NEET MCQ
AIPMT 2001
Mn and Mp represent the mass of neutron and proton respectively. An element having mass M has N neutrons and Z protons, then the correct relation will be
A.
M < {N $ \cdot $ Mn + Z $ \cdot $ Mp}
B.
M > {N $ \cdot $ Mn + Z $ \cdot $ Mp}
C.
M = {N $ \cdot $ Mn + Z $ \cdot $ Mp}
D.
M = N {Mn + Mp}
2001 NEET MCQ
AIPMT 2001
X(n, $\alpha $) ${}_3^7$Li, then X will be
A.
${}_5^{10}$ B
B.
${}_5^9$ B
C.
${}_5^{11}$ Be
D.
${}_2^4$ He.
2001 NEET MCQ
AIPMT 2001
Energy released in nuclear fission is due to
A.
some mass is converted into energy
B.
total binding energy of fragments is more than the binding energy of parantal element
C.
total binding energy of fragments is less than the binding energy of parental element
D.
total binding energy of fragments is equal to the binding energy of parental element.
2001 NEET MCQ
AIPMT 2001
The energy of hydrogen atom in nth orbit is En then the energy in nth orbit of singly ionised helium atom will be
A.
4En
B.
En/4
C.
2En
D.
En/2
2001 NEET MCQ
AIPMT 2001
The interplanar distance in a crystal is 2.8 $ \times $ 10$-$8 m. The value of maximum wavelength which can be diffracted
A.
2.8 $ \times $ 10$-$8 m
B.
5.6 $ \times $ 10$-$8 m
C.
1.4 $ \times $ 10$-$8 m
D.
7.6 $ \times $ 10$-$8 m
2001 NEET MCQ
AIPMT 2001
Half life of a radioactive element is 12.5 hour and its quantity is 256 g. After how much time its quantity will remain 1 g?
A.
50 hrs
B.
100 hrs
C.
150 hrs
D.
200 hrs
2000 NEET MCQ
AIPMT 2000
Maximum frequency of emission is obtained for the transition
A.
n = 2 to n = 1
B.
n = 6 to n = 2
C.
n = 1 to n = 2
D.
n = 2 to n = 6.
2000 NEET MCQ
AIPMT 2000
The relation between $\lambda $ and T1/2 as (T1/2 $ \to $ half life)
A.
T1/2 = ${{\ln 2} \over \lambda }$
B.
T1/2 ln2 = $\lambda $
C.
T1/2 = ${1 \over \lambda }$
D.
($\lambda $ + T1/2) = ln2
2000 NEET MCQ
AIPMT 2000
Nuclear fission is best explained by
A.
liquid droplet theory
B.
Yukawa $\pi $-meson theory
C.
independent particle model of the nucleus
D.
proton-proton cycle.
2000 NEET MCQ
AIPMT 2000
The life span of atomic hydrogen is
A.
fraction of one second
B.
one year
C.
one hour
D.
one day
2000 NEET MCQ
AIPMT 2000
For the given reaction, the particle X is
$_6{C^{11}} \to {}_5{B^{11}} + {\beta ^ + } + X$
A.
neutron
B.
anti neutrino
C.
neutrino
D.
proton
2000 NEET MCQ
AIPMT 2000
When an electron does transition from n = 4 to n = 2, then emitted line spectrum will be
A.
first line of Lyman series
B.
second line of Balmer series
C.
first line of Balmer series
D.
second line of Paschen series.