Assertion:  ⁹⁰Sr from the radioactive fall out from a nuclear bomb ends up in the bones of human beings through the milk consumed by them. It causes impairment of production of red blood cells.

Reason: The energies β-particles emitted in the decay of  ⁹⁰Sr damage the bone marrow.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

What is the amount of energy released by deuterium and tritium fusion?  [ Given: ${\mathrm{M}}_{{}_1{}^2\mathrm{H}}$ =2.0141024 u,  ${\mathrm{M}}_{{}_1{}^3\mathrm{H}}$ = 3.0160504 ,  ${\mathrm{M}}_{{}_0{}^1\mathrm{n}}$ = 1.0086654 u ]

• 60.6 eV

• 12.6 eV

• 17.6 eV

• 28.3 eV

What is the energy of photon whose wavelength is 6840 $\stackrel{\circ }{\mathrm{A}}$ ?

• 1.81 eV

• 3.6 eV

• $-$ 13.6 eV

• 12.1 eV

Calculate power output of  ${}_{92}{}^{235}\mathrm{U}$ reactor, if it is takes 30 days to use up 2 kg of fuel, and if each fission gives  185 MeV of useable energy. Avogadro's number = 6 × 10²³ / mol?

• 56.3 MW

• 60.3 MW

• 58.3 MW

• 54.3 MW

Assertion: Heavy water is a better moderator than normal water.

Reason: Heavy water absorbs neutrons more efficiently than normal water.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion:  ⁹⁴Sr from the radioactive fall out from a nuclear bomb ends up in the bones of human beings through the milk consumed by them. It causes impairment of the production of red blood cells. 

Reason: The energetics  β-particles emitted in the decay of  ⁹⁴Sr damage the bone marrow.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

The operation of a nuclear reactor is said to be critical, if the multiplication factor  ( K ) has a value

• 1

• 1.5

• 2.1

• 2.5

118.

${}_{98}{}^{238}\mathrm{U}$ has  92  protons  and  238  nucleons. It decays by emitting an alpha particle and becomes

• ${}_{92}{}^{238}\mathrm{U}$

• ${}_{90}{}^{234}\mathrm{Th}$

• ${}_{92}{}^{235}\mathrm{U}$

• ${}_{93}{}^{237}\mathrm{Np}$

The foil bone has a ¹⁴C : ¹²C  ratio, which is  [ 1/16 ] of  that in a living animal bone. If the half-life time of  ¹⁴C  is  5730 years, then the age of the fossil bone is

• 11460 years

• 17190 years

• 22920 years

• 45840 years

Which one of the following is a possible nuclear reaction?

• ${}_5{}^{10}\mathrm{B} + {}_2{}^4\mathrm{He} \to {}_7{}^{13}\mathrm{N} + {}_1{}^1\mathrm{H}$

• ${}_{11}{}^{23}\mathrm{Na} + {}_1{}^1\mathrm{H} \to {}_{10}{}^{ 20}\mathrm{Ne} + {}_2{}^4\mathrm{He}$

• ${}_{93}{}^{239}\mathrm{Np} \to {}_{94}{}^{239}\mathrm{Pu} + {\mathrm{\beta }}^{-} + \overline{\mathrm{\nu }}$

• ${}_7{}^{11}\mathrm{N} + {}_1{}^1\mathrm{H} \to {}_6{}^{12}\mathrm{C} + {\mathrm{\beta }}^{-} + \overline{\mathrm{\nu }}$