The most penetrating radiation out of the following is
A.
$$\gamma $$-rays
B.
$$\alpha $$-particles
C.
$$\beta $$-rays
D.
X-rays
Answer :
$$\gamma $$-rays
Solution :
The penetrating power of radiation is directly proportional to the energy of its photon.
Energy of photon $$ = \frac{{hc}}{\lambda } \propto \frac{1}{\lambda }\left( {{\text{wavelength}}} \right)$$
∴ Penetrating power $$ \propto \frac{1}{\lambda }\left( {{\text{wavelength}}} \right)$$
Since, $$\lambda $$ is minimum for $$\gamma $$-rays, so penetrating power is maximum for $$\gamma $$-rays.
Releted MCQ Question on Modern Physics >> Atoms or Nuclear Fission and Fusion
In the nuclear fusion reaction
$$_1^2H + _1^3H \to _2^4He + n$$
given that the repulsive potential energy between the two
nuclei is $$ \sim 7.7 \times {10^{ - 14}}J,$$ the temperature at which the gases must be heated to initiate the reaction is nearly
[Boltzmann’s Constant $$k = 1.38 \times {10^{ - 23}}J/K$$ ]
The binding energy per nucleon of deuteron $$\left( {_1^2H} \right)$$ and helium nucleus $$\left( {_2^4He} \right)$$ is $$1.1\,MeV$$ and $$7\,MeV$$ respectively. If two deuteron nuclei react to form a single helium nucleus, then the energy released is