. In this reaction how many and particles are emitted
(a) 6, 3 (b) 3, 4
(c) 4, 3 (d) 3, 6
The phenomenon of radioactivity is
(1) Exothermic change which increases or decreases with temperature
(2) Increases on applied pressure
(3) Nuclear process does not depend on external factors
(4) None of the above
If half life of radium is 77 days. Its decay constant in day will be
(1) /day
(2) /day
(3) /day
(4) /day
Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion 5 billion years ago. The other was created in a nuclear reactor 5 minutes ago. The probability of decay during the next time is
(1) Different for each nuclei
(2) Nuclei created in explosion decays first
(3) Nuclei created in the reactor decays first
(4) Independent of the time of creation
An -particle of 5 MeV energy strikes with a nucleus of uranium at stationary at a scattering angle of 180o. The nearest distance up to which -particle reaches the nucleus will be of the order of:
(1) 1 Å
(2)
(3)
(4)
A neutron with velocity V strikes a stationary deuterium atom. Its kinetic energy changes by a factor of
(1)
(2)
(3)
(4) None of these
The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is 1.4 .The average earth- sun distance is metres. The mass lost by the sun per day is
(1 day = 86400 seconds)
(a) (b)
(c) (d)
The binding energy per nucleon of is 7.97 MeV and that of is 7.75 MeV. The energy (in MeV) required to remove a neutron from is
(a) 3.52 (b) 3.64
(c) 4.23 (d) 7.86
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
(1) 0.026 MeV
(2) 0.051 MeV
(3) 0.079 MeV
(4) 0.105 MeV
For uranium nucleus how does its mass vary with volume
(1)
(2)
(3)
(4)