The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is 1.4 $\mathrm{kilowatt}/{\mathrm{m}}^{2}$.The average earth- sun distance is $1.5×{10}^{11}$ metres. The mass lost by the sun per day is
(1 day = 86400 seconds)
(a)           (b)
(c)          (d)

Concept Questions :-

Mass-energy equivalent
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Difficulty Level:

The binding energy per nucleon of ${\mathrm{O}}^{16}$ is 7.97 MeV and that of ${\mathrm{O}}^{17}$ is 7.75 MeV. The energy (in MeV) required to remove a neutron from ${\mathrm{O}}^{17}$ is
(a) 3.52                 (b) 3.64
(c) 4.23                 (d) 7.86

Concept Questions :-

Nuclear binding energy
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Difficulty Level:

The rest energy of an electron is 0.511 MeV. The electron is accelerated from rest to a velocity 0.5 c. The change in its energy will be
(a) 0.026 MeV            (b) 0.051 MeV
(c) 0.079 MeV            (d) 0.105 MeV

Concept Questions :-

Mass-energy equivalent
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

For uranium nucleus how does its mass vary with volume

(a) $\mathrm{m}\propto \mathrm{V}$           (b) $\mathrm{m}\propto 1/\mathrm{V}$
(c)        (d) $\mathrm{m}\propto {\mathrm{V}}^{2}$

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High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The rest mass of an electron as well as that of positron is 0.51 MeV. When an electron and positron are annihilated, they produce gamma-rays of wavelength(s)-

(a) 0.012 Å               (b) 0.024 Å
(c) 0.012 Å to $\infty$      (d) 0.024 Å to $\infty$

Concept Questions :-

Mass-energy equivalent
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In the nuclear fusion reaction ${}_{1}{}^{2}\mathrm{H}+{}_{1}{}^{3}\mathrm{H}\to {}_{2}{}^{4}\mathrm{He}+\mathrm{n}$ given that the repulsive potential energy between the two nuclei is , the temperature at which the gases must be heated to initiate the reaction is nearly
[Boltzmann’s constant )
(a)            (b)
(c)            (d)

Concept Questions :-

Mass-energy equivalent
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A nucleus with mass number 220 initially at rest emits an $\mathrm{\alpha }$-particle. If the Q value of the reaction is 5.5 MeV, calculate the kinetic energy of the $\mathrm{\alpha }$-particle

(a) 4.4 MeV             (b) 5.4 MeV
(c) 5.6 MeV             (d) 6.5 MeV

Concept Questions :-

Types of decay
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Difficulty Level:

The half life of radioactive Radon is 3.8 days. The time at the end of which 1/20 th of the Radon sample will remain undecayed is
(Given ${\mathrm{log}}_{10}\mathrm{e}=0.4343$
(a) 3.8 days               (b) 16.5 days
(c) 33 days                (d) 76 days

Concept Questions :-

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

If 10% of a radioactive material decays in 5 days, then the amount of original material left after 20 days is approximately
(a) 60%              (b) 65%
(c) 70%              (d) 75%

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High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A radioactive isotope X with a half-life of $1.37×{10}^{9}$ years decays to Y which is stable. A sample of rock from the moon was found to contain both the elements X and Y which were in the ratio of 1 : 7. The age of the rock is
(a) $1.96×{10}^{8}$ years         (b) $3.85×{10}^{9}$ years
(c) $4.11×{10}^{9}$years          (d) $9.59×{10}^{9}$ years

Concept Questions :-