$_1H^1 + _1H^1 + _1H^2 \to X + _{+1}e^0 + \text{energy}$. The emitted particle $X$ is:

In a material medium,when a positron meets an electron,both particles annihilate,leading to the emission of two gamma-ray photons. This process forms the basis of an important diagnostic procedure called:

In the options given below, let $E$ denote the rest mass energy of a nucleus and $n$ a neutron. The correct option is:

The binding energy of a deuteron is $2.2 \, MeV$ and the binding energy of $_2^4He$ is $28 \, MeV$. If two deuterons fuse to form a $_2^4He$ nucleus,the energy released is ...... $MeV$.

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

The energy released in the fusion of $2 \ kg$ of hydrogen deep in the sun is $E_{H}$ and the energy released in the fission of $2 \ kg$ of ${ }^{235} U$ is $E_U$. The ratio $\frac{E_H}{E_U}$ is approximately :
(Consider the fusion reaction as $4{ }_1^1 H + 2 e^{-} \rightarrow { }_2^4 He + 2 \nu + 6 \gamma + 26.7 \ MeV$,energy released in the fission reaction of ${ }^{235} U$ is $200 \ MeV$ per fission nucleus and $N_{A} = 6.023 \times 10^{23}$ )