CBSE
Multiple Choice QuestionsThe phenomenon of radioactivity is :
exothermic change which increases or decreases with temperature
increases on applied pressure
nuclear process does not depend on external factors
none of the above
Two radioactive substances A and B have decay constants 5 λ and λ respectively. At t = 0 they have the same number of nuclei. The ratio of number of nuclei of A to those of B will be after a time interval
4λ
2λ
Fission of nuclei is possible because the binding energy per nucleon in them
increases with mass number at high mass numbers
decreases with mass number at high mass numbers
increases with mass number at low mass numbers
decreases with mass number at low mass numbers
If the energy released in the fission of one nucleus is 3.2x10-11J, then number of nuclei required per second in a power plant of 16 kW is
In the reaction, if the binding energies of are respectively a, b and c (in MeV), then the energy in this reaction is released in this reaction is
c + a - b
c - a - b
a + b + c
a +b - c
In the reaction given below . How many α and β particles are emitted?
6α, 3β
3α, 4β
4α, 3β
3α,6β
In any fission process the ratio is
less than 1
greater than 1
greater than 1
depends on the mass of parent nucleus
The half-life of a radioactive substance is 3.6 days. How much of 20 mg of this radioactive substance will remain after 36 days?
0.0019 mg
1.019 mg
1.109 mg
0.019 mg
In radioactive decay process, the negatively charged emitted -particles are
the electrons present inside the nucleus
the electrons produced as a result of the decay of neutrons inside the nucleus
the electrons produced as a result of collisions between atoms
the electrons orbiting around the nucleus
If an electron has orbital angular momentum quantum number l =7 then it will have an orbital angular momentum equal to
