HARD
JEE Main/Advance
IMPORTANT
Earn 100

A radioactive nuclide is produced at a constant rate x nuclei per second. During each decay, E0 energy is released 50% of this energy is utilised in melting ice at 0°C. Find mass of ice that will melt in one mean life. (λ= decay constant, L1= Latent heat of fusion.)

Important Questions on Nuclear Physics

EASY
JEE Main/Advance
IMPORTANT

In a fusion reactor the reaction occurs in two stages (i) Two deuterium D12 nuclei fuse to form a tritium  T13. nucleus with a proton as product. The reaction may be represented as D(D, p) T. (ii) A tritium nucleus fuses with another deuterium nucleus to form a helium H24e nucleus with neutron as another product. The reaction is represented as T(D,n)α. Find:

(i) the energy release in each stage.

(ii) The energy release in the combined reaction per deuterium &

(iii) What % of the mass of the initial deuterium is released in the form of energy.

Given: D12=2.014102u; T13=3.016049u;H24e=4.002603u;P11=1.00785u;n01=1.008665u

HARD
JEE Main/Advance
IMPORTANT
The element curium C96248m has a mean life of 1013 second. Its primary decay modes are spontaneous fission and α- decay, the former with a probability of 8% and the latter with a probability of 92%. Each fission releases 200MeV of energy. The masses involved in decay are as follows : C96248m=248.072220u94P94244u=244.064100u and H24e=4.002603u. Calculate the total power produced. Assume a sample of 1020Cm atom.
HARD
JEE Main/Advance
IMPORTANT
A small bottle contains powdered beryllium Be & gaseous radon which is used as a source of α-particles. Neutrons are produced when α-particles of the radon react with beryllium. The yield of this reaction is 14000 i.e. only one α-particle out of 4000 induced the reaction. Find the amount of radon Rn222 originally introduced into the, source, if it produces 1.2×106 neutrons per second after 7.6 days. T12 of Rn=3.8 days]
HARD
JEE Main/Advance
IMPORTANT
A body of mass m0 is placed on a smooth horizontal surface. The mass of the body is decreasing exponentially with disintegration constant λ. Assuming that the mass is ejected backward with a relative velocity v0. Initially the body was at rest. Find the velocity of body after time t.
HARD
JEE Main/Advance
IMPORTANT
A radionuclide with disintegration constant λ is produced in a reactor at a constant rate α nuclei per sec. During each decay energy E0 is released. 20% of this energy is utilised in increasing the temperature of water. Find the increase in temperature of m mass of water in time t. Specific heat of water is S. Assume that there is no loss of energy through water surface.