When a deuterium is bombarded on \({}_{8}^{16}\mathrm{O}\) nucleus, an \(\alpha\text-\)particle is emitted, then the product nucleus is:

1.	\({}_{7}^{13}\mathrm{N}\)	2.	\({}_{5}^{10}\mathrm{B}\)
3.	\({}_{4}^{9}\mathrm{Be}\)	4.	\({}_{7}^{14}\mathrm{N}\)

The mass of \({}_{7}^{15}\mathrm{N}\) is \(15.00011\) amu, mass of \({}_{8}^{16}\mathrm{O}\) is \(15.99492\) amu and \(m_p = 1.00783\) amu. Determine the binding energy of the last proton of \({ }_{8}^{16}\mathrm{O}\).
1. \(2.13\) MeV
2. \(0.13\) MeV 
3. \(10\) MeV 
4. \(12.13\) MeV

The rate of disintegration of a fixed quantity of a radioactive substance can be increased by:

1. increasing the temperature.

2. increasing the pressure.

3. chemical reaction.

4. it is not possible.

The power obtained in a reactor using \(\mathrm{U}^{235}\) disintegration is \(1000\) kW. The mass decay of \(\mathrm{U}^{235}\) per hour is:
1. \(1\) microgram
2. \(10\) microgram
3. \(20\) microgram
4. \(40\) microgram

The counting rate observed from a radioactive source at t = 0 second was 1600 counts per second and at t = 8 seconds it was 100 counts per second. The counting rate observed, as counts per second, at t = 6 seconds will be:

1. 400

2. 300

3. 200

4. 150

Half-lives of two radioactive substances A and B respectively are 20 min and 40 min.  Initially, the samples of A and B have an equal number of nuclei. After 80 min the ratio of the remaining number of A and B nuclei is:

1. 1 : 16

2. 4 : 1

3. 1 : 4 

4. 1 : 1

What fraction of a radioactive material will get disintegrated in a period of two half-lives?

1. whole

2. half

3. one-fourth

4. three-fourth

In a radioactive material, the activity at time $t_1$ is $R_1$ and at a later time, $t_2$ is $R_2$. If the decay constant of the material is $\lambda$, then:

1. $R_1=R_2{e}^{-\lambda \left(t_1-t_2\right)}$   

2. $R_1=R_2{e}^{\lambda \left(t_1-t_2\right)}$

3. $R_1=R_2\left(\frac{t_2}{t_1}\right)$ 

4. $R_1=R_2$

In the nuclear reaction: \(\mathrm{X}\left(n,\alpha\right){}_{3}^{7}\mathrm{Li}\) the term \(\mathrm{X}\) will be:

A and B are two radioactive substances whose half-lives are 1 and 2 years respectively. Initially 10 g of A and 1 g of B is taken. The time (approximate) after which they will have the same quantity remaining is:

1. 6.62 yr

2. 5 yr   

3. 3.2 yr 

4. 7 yr