Nuclear Physics

A sample has half life of $10^{33}$ year. If initial number of nuclei of the sample is $26 \times 10^{34}$. Then find out the number of nuclei decayed in 1 year?

If half life of an element is 69.3 hours then how much of its percent will decay between $10^{\text {th }}$ and $11^{\text {th }}$ hour. Initial activity $=50 \mu \mathrm{C}_i$.

The half-life of ${ }^{215} \mathrm{At}$ is $100 \mu \mathrm{s}$. The time taken for the radioactivity of a sample of ${ }^{215}$ At to decay to $1 / 16^{\text {th }}$ of its initial value is

If decay constant of a radioactive sample is 0.05 per year, then find the time (in year) for which sample will decay by $75 \%$.

Assertion : Mass is not conserved, but mass and energy are conserved as a single entity is called mass-energy. Reason: Mass and energy are inter-convertible in accordance with Einstein's relation, $E=m c^2$.

In a nuclear fusion reaction, two nuclei, $A$ and $B$ fuse to produce a nucleus $C$, releasing an amount of energy $\Delta E$ in the process. If the mass defects of the three nuclei are $\Delta M_A$, $\Delta M_B$ and…

The activity of a sample of radioactive material is $A_1$ at time $t_1$ and $A_2$ at time $t_2\left(t_2>t_1\right)$. If its mean life is $T$, then

Assertion : Thermonuclear fusion reactions may become the source of unlimited power for the mankind. Reason : A single fusion event involving isotopes of hydrogen produces more energy than energy from nuclear fission of…

A neutron in a nuclear reactor collides head on elastically with the nucleus of a carbon atom initially at rest. The fraction of kinetic energy transferred from the neutron to the carbon atom is

Two radioactive materials $X_1$ and $X_2$ have decay constants $6 \lambda$ and $3 \lambda$ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of $X_1$ to that of $X_2$…

Assertion : Unlike electric force and gravitational forces, nuclear force has limited range. Reason : Nuclear force do not obey inverse square law.

Assertion : Heavy water is used as moderator in nuclear reactor. Reason: Water cool down the fast neutron.