A nuclear decay is expressed as:
$_{6}^{11}\mathrm{C}\rightarrow _{5}^{11}\mathrm{B}+\beta^{+}+\mathrm{X}$
Then the unknown particle $X$ is:
1. neutron 
2. antineutrino
3. proton 
4. neutrino

A nuclear reaction given by; ${ }_{Z}^{A} ~{X} \rightarrow{ }_{Z+1}^{A} {Y}+e^{-}+\bar{v}$ represents:

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 energy released by the fission of one  uranium atom is 200 MeV. The number of fission per second required to produce 3.2 W of power is (Take, 1 eV = 1.6$\times$${10}^{-19} J$) 

1. ${10}^7$ 

2. ${10}^{10}$ 

3. ${10}^{15}$

4. ${10}^{11}$

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

Light energy emitted by stars is due to

1. Breaking of nuclei 

2.Joining of nuclei       

3. Burning of nuclei

4. Reflection of solar light