Video Lecture
Theory For Making Notes
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Practice Questions (Basic Level)
1.
The nuclear radius of Pb208 is 8.874 fm. What will be the nuclear radius of Ca44?
(a) 5. 483fm
(b) 5.286 fm
(c) 0.146 fm
(d) 4.326 fm
Ans (b)
2.
The mass defect for the nucleus of helium is 0.0303u. What is the binding energy per nucleus for helium in MeV?
(a)28
(b)7
(c)4
(d)1.
Ans (b)
3.
If M is atomic mass, A is mass number, then \left( {\frac{{M-A}}{M}} \right) is called
(a)Binding energy
(b)Fermi energy
(c)Mass defect
(d)Packing fraction.
Ans (d)
4.
The more readily fissionable isotope of uranium has an atomic mass of
(a)238u
(b)236u
(c)235u
(d)234u.
Ans (c)
5.
Fusion reactions takes place at about
(a)3 × 102 K
(b)3 × 103 K
(c)3 × 104 K
(d)3 × 106 K.
Ans (d)
6.
The mass density of a nucleus varies with mass number A as
(a)A2
(b)A
(c)constant
(d)1/A
Ans (c)
7.
In nuclear fission, 0.1 % mass is converted into energy. The energy released by the fission of 1 kg mass is
(a)2.5 × 105 k Wh
(b)2.5 × 107 k Wh
(c)2.5 × 106 k Wh
(d)2.5 × 10–7 k Wh.
Ans (b)
8.
In a given nuclear reaction 2He4 + Z X _____ Z+2Y A + 3 + K, K is
(a) electron
(b) positron
(c) proton
(d) neutron
Ans (d)
9.
A nucleus with A = 235 splits into two nuclei whose mass numbers are in the ratio 2 : 1. If R0 = 1.4 fm, find the radii of the new nuclei.
(a) 5.99 fm, 1.45 fm
(b) 5.99 fm, 0.23 fm
(c) 5.99 fm, 8.36 fm
(d) 5.99 fm, 7.55 fm
Ans (d)
10.
Calculate the binding energy per nucleon for a 6C12 nucleus. Atomic mass of 6C12 = 12u, mass of a proton = 1.007825u, mass of a neutron = 1.008665u.
(a) 1.00 MeV
(b) 7.68 MeV
(c) 2.33 MeV
(d) 0.32 MeV
Ans (b)
11.
A nuclear reaction used U235 as fuel as an output of 106 W. How much uranium is consumed per hour? The energy released per fission is 200 MeV. Given Avogadro’s number = 6.023 × 1023 mol–1.
(a) 1.0354 g
(b) 0.025 g
(c) 0.0439 g
(d) 2.2339 g
Ans (c)
Practice Questions (JEE Main Level)
1.
Calculate the binding energy of a deutron. Given that
mass of proton = 1.007825u
mass of neutron = 1.008665u
mass of a deutron = 2.014103u.
(a) 2.2 MeV
(b) 3.94 MeV
(c) 2.44 MeV
(d) 0.3 MeV
Ans (a)
2.
If element with principal quantum number n> 4 were not allowed in nature, the number of possible elements would be
(a) 60
(b) 31
(c) 4
(d) 64.
Ans (a)
3.
In stable nuclei, the number of neutrons (N) is related to the number of electrons (Z) in the neutral atom in general as
(a) N > Z
(b) N = Z
(c) N < Z
(d) N ³ Z.
Ans (d)
4.
When a lithium nucleus (3Li7) is bombarded with certain particles, only two alpha particles are produced. The bombarding particles are
(a) photons
(b) electrons
(c) protons
(d) deutrons.
Ans (c)
5.
From the following equations pick out the possible nuclear fusion reactions
(a) _{\text{6}}{{\text{C}}^{{\text{13}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{7}}}{{\text{N}}^{{\text{14}}}}+\text{4}\text{.3MeV}
(b) _{\text{6}}{{\text{C}}^{{\text{12}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{7}}}{{\text{N}}^{{\text{13}}}}+\text{2}\,\text{MeV}
(c) _{\text{7}}{{\text{N}}^{{\text{14}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{8}}}{{\text{O}}^{{\text{15}}}}+\text{7}.3\,\text{MeV}
(d) _{{\text{92}}}{{\text{U}}^{{\text{235}}}}+{{\,}_{\text{0}}}{{n}^{\text{1}}}\to {{\,}_{{\text{54}}}}\text{X}{{\text{e}}^{{\text{140}}}}+{{\,}_{{38}}}\text{S}{{\text{r}}^{{94}}} +2\,{{(}_{0}}{{n}^{1}})+\gamma +200\text{MeV}\text{.}
Ans (b)
6.
The mass number of He is 4 and that for sulphur is 32. The radius of sulphur nucleus is larger than that of helium by times
(a) \sqrt{8}
(b) 4
(c) 2
(d) 8.
Ans (c)
7.
M, Mn and Mp denote the masses of a nucleus ZXA, a neutron and proton respectively. If the nucleus is separated into its individual protons and neutrons then
(a) M=(A-Z){{M}_{n}}+Z{{M}_{p}}
(b) M=Z{{M}_{n}}+(A-Z){{M}_{p}}
(c) M>(A-Z){{M}_{n}}+Z{{M}_{p}}
(d) M<(A-Z){{M}_{n}}+Z{{M}_{p}}.
Ans (d)
8.
If all the atoms of 1 kg of deuterium undergo fusion, approximately how much energy could be released, if the fusion reaction is _{\text{1}}{{\text{H}}^{\text{2}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{2}}}\to {{\,}_{\text{2}}}\text{H}{{\text{e}}^{\text{3}}}+{{\,}_{\text{0}}}{{\text{n}}^{\text{1}}}+\text{3}\text{.8MeV}
(a)9 × 1013 J
(b)9 × 1011 calorie
(c)9 × 1012 kWh
(d)9 × 107 kWh.
Ans (a)
9.
Assuming that about 20 MeV of energy is released per fusion reaction _{\text{1}}{{\text{H}}^{\text{2}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{2}}}\to {{\,}_{\text{0}}}{{n}^{\text{1}}}+{{\,}_{\text{2}}}\text{H}{{\text{e}}^{\text{3}}} then the mass of 1H2 consumed per day in a fusion reactor of power 1 Megawatt will approximately be
(a) 0.001 gm
(b)0.1 gm
(c) 10.0 gm
(d) 1000 gm.
Ans (b)
10.
Given that mass of proton = 1.00813u, mass of neutron is 1.00894u and mass of
a-particle is 4.00388u, the binding energy of alpha particle is
(a) 28.172 MeV
(b) 27.172 MeV
(c) 13.52 MeV
(d) 56.321 MeV
Ans (a)
11.
Nuclear radius of 8O16 is 3 fermi. The nuclear radius of 82Pb205 is
(a) 5.02 fermi
(b) 6.02 fermi
(c) 7.02 fermi
(d) 8.02 fermi
Ans (c)
12.
Let mp be the mass of a proton, mn be the mass of a neutron, M1 be the mass of 10He20 nucleus and M2 the mass of 20Ca40 nucleus. Then
(a) M2 = 2M1
(b) M2> 2M1
(c) M2< 2M1
(d) M1< 10 (mp + mn)
Ans (d)
13.
If the nuclear force between two protons, two neutrons and between proton and neutron is denoted by Fpp, Fnn and Fpn respectively then
(a) Fpp = Fnp = Fnn
(b) Fpp¹Fnp but Fpp = Fnp
(c) Fpp = Fnn¹Fpn
(d) Fpp¹Fnn¹Fpn.
Ans (a)
14.
The binding energies per uncleon for a deutron and an a-particle are X1 and X2 respectively. What will be the energy Q released in the reaction? _{\text{1}}^{\text{2}}\text{H}+\,_{\text{1}}^{\text{2}}\text{H}\to \,_{\text{2}}^{\text{4}}\text{He}+\text{Q}
(a) 4 (X2 – X1)
(b) 2 (X2 – X1)
(c) 4 (X1 + X2)
(d) 2 (X1 + X2).
Ans (a)
15.
The real mass, MN of a stable nucleus differs from the total mass of its constituents (protons and neutrons) MT, in such a way that
(a) MN>MT
(b) MN is slightly smaller than MT
(c) MN = MT
(d) MN>>MT.
Ans (b)
16.
If the speed of light were \frac{2}{3} of its present value, the energy released in a given atomic explosion will be decreased by a fraction of
(a) \frac{2}{3}
(b) \frac{4}{9}
(c) \frac{5}{9}
(d) \frac{2}{9}.
Ans (b)
17.
The binding energy per nucleon of deutron and helium atom is 1.1 MeV and 7 MeV respectively. If two deutron atoms react to form a single helium, then the energy released is
(a) 13.9 MeV
(b) 26.9 MeV
(c) 23.6 MeV
(d) 19.2 MeV.
Ans (b)
18.
What is the power output of 92U235 reactor if it takes 30 days to use up 2 kg of fuel, and if each fission gives 185 MeV of usable energy? Avogadro’s number N = 6.02 ´ 1026 per kilomole.
(a) 50.65 MW
(b) 55.32 MW
(c) 57.00 MW
(d) 58.46 MW
Ans (d)
19.
Assuming all the energy released by the fission of each _{{92}}^{{235}}U nucleus (190 MeV) is absorbed by water, how many _{{92}}^{{235}}U atoms must undergo fission to warm 1 g of water by 1C°?
(a) 0.23 x 1011
(b) 1.87 x 1011
(c) 1.38 x 1011
(d) 5.83 x 1011
Ans (c)
Practice Questions (JEE Advance Level)
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.