A gamma ray photon creates an electron- positron pair. If the rest mass energy of an electron is 0.5 MeV and the total K.E. of the electron- positron pair is 0.78 MeV, then the energy of the gamma ray photon must be
(a) 0.78 MeV                  (b) 1.78 MeV
(c) 1.28 MeV                  (d) 0.28 MeV

Concept Questions :-

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

Difficulty Level:

Which of the following statement is true
(a) ${}_{78}\mathrm{Pt}_{192}$ has 78 neutrons
(b) ${}_{84}\mathrm{Po}_{214}\to {}_{82}\mathrm{Pb}_{210}+{\mathrm{\beta }}^{-}$
(c) ${}_{92}U_{238}\to {}_{90}\mathrm{Th}_{234}+{}_{2}\mathrm{He}_{4}$
(d) ${}_{90}\mathrm{Th}_{234}\to {}_{91}\mathrm{Pa}_{234}+{}_{2}\mathrm{He}_{4}$

Concept Questions :-

Types of decay
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Fast neutrons can easily be slowed down by
(a) The use of lead shielding
(b) Passing them through water
(c) Elastic collisions with heavy nuclei
(d) Applying a strong electric field

Concept Questions :-

Nuclear reactor
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

When ${}_{92}\mathrm{U}_{235}$ undergoes fission, 0.1% of its original mass is changed into energy. How much energy is released if 1kg of ${}_{92}\mathrm{U}_{235}$ undergoes fission

(a)             (b)
(c)             (d)

Concept Questions :-

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

Difficulty Level:

$\mathrm{\gamma }$-rays radiation can be used to create electron-positron pair. In this process of pair production, $\mathrm{\gamma }$-rays energy cannot be less than
(a) 5.0 MeV                (b) 4.02 MeV
(c) 15.0 MeV               (d) 1.02 MeV

Concept Questions :-

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

Difficulty Level:

A reaction between a proton and ${}_{8}\mathrm{O}_{18}$ that produces ${}_{9}\mathrm{F}_{18}$ must also liberate
(a) ${}_{0}\mathrm{n}_{1}$         (b) ${}_{1}\mathrm{e}_{0}$
(c) ${}_{1}\mathrm{n}_{0}$         (d) ${}_{0}\mathrm{e}_{1}$

Concept Questions :-

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

Difficulty Level:

In the nuclear reaction ${}_{92}\mathrm{U}_{238}\to {}_{\mathrm{z}}\mathrm{Th}_{\mathrm{A}}+{}_{2}\mathrm{He}_{4}$ , the values of A and Z are
(a) A = 234, Z = 94              (b) A = 234, Z = 90
(c) A = 238, Z = 94              (d) A = 238, Z = 90

Concept Questions :-

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

Difficulty Level:

If 200 MeV energy is released in the fission of a single ${\mathrm{U}}^{235}$ nucleus, the number of fissions required per second to produce 1 kilowatt power shall be (Given
(a) $3.125×{10}^{13}$           (b) $3.125×{10}^{14}$
(c) $3.125×{10}^{15}$           (d) $3.125×{10}^{16}$

Concept Questions :-

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

Difficulty Level:

In nuclear fission, the fission reactions proceeds with a projectile. Which of the following suits the best

(a) Slow proton             (b) Fast neutron
(c) Slow neutron           (d) None of these

Concept Questions :-

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

Difficulty Level:

In the nuclear reaction  ${}_{85}\mathrm{X}_{297}\to \mathrm{Y}+4\mathrm{\alpha }$, Y is

(a) ${}_{76}\mathrm{Y}_{287}$             (b) ${}_{77}\mathrm{Y}_{285}$
(c) ${}_{77}\mathrm{Y}_{281}$             (d) ${}_{77}\mathrm{Y}_{289}$

Concept Questions :-