Nuclei practice · Mixed difficulty

Hydrogen bomb is based upon

A radioactive sample decays by $\beta$-emission. In first two seconds '$n$' $\beta$-particles are emitted and in next 2 seconds, '$0.25n$' $\beta$-particles are emitted. The half-life of radioactive nuclei is:

Light energy emitted by stars is due to

$1\,\,g$ of hydrogen is converted into $0.993\,\,g$ of helium in a thermonuclear reaction. The energy released is

In any fission process, the ratio of
$\frac{{{\text{mass}}\,{\text{of}}\,{\text{fission}}\,{\text{products}}}}{{{\text{mass}}\,{\text{of}}\,{\text{parent}}\,{\text{nucleus}}}}$ is

Energy generation in stars is mainly due to

The $\beta$-particles of a radioactive metal originate from

The particle emitted in the decay of ${ }_{92}^{238} \mathrm{U}$ to ${ }_{92}^{234} \mathrm{U}$

Assertion (A): Two different radioactive substances have initially same number of nuclei. Their decay constants are $\lambda_{1}$ and $\lambda_2\left( < \lambda_1\right)$, then initially first radioactive substance decays at faster rate.
Reason (R): Half-life of first radioactive substance is more.

Protons and neutrons are built out of

Assertion: Heavy water preferred over ordinary water as a moderator in reactors.
Reason: Heavy water, used for slowing down the neutrons, has lesser absorption probability of neutrons than ordinary water.

In a mean life of a radioactive sample

Statement-I: The BE per nucleon of the fused heavier nuclei is more than the B.E per nucleon of the lighter nuclei.

Statement-II: The final system is more tightly bound to the initial system.

A radioactive nucleus can decay simultaneously by two different processes which have decay constant ${\lambda _1}\,\,\mathrm{and}\,\,{\lambda _2}$.The effective decay constant of the nuclide is $\lambda ,$ where

Half life of radioactive element depends upon

The exchange particles responsible for nuclear weak interaction are

Outside a nucleus

The correct order of ionizing capacity of $\alpha ,\beta$ and $\gamma -$ rays is

The binding energy per nucleon for deuteron and helium are $\mathrm{1}\mathrm{.1}\,\,\mathrm{MeV}$ and $\mathrm{7}\mathrm{.0}\,\,\mathrm{MeV}$. The energy released when two deuterons fuse to form a helium nucleus is

As compound $^{12}C$ atom, $^{14}C$ atom has

The radius of the ${}_2He^4$ nucleus is 3 fermi. The radius of ${}_{82}Pb^{206}$ nucleus will be

Select the true statement from the following. Nuclear force is

What is approximately the ratio of nuclear radii of gold isotope $_{79}^{238}Au$ and silver isotope $_{47}^{108}Ag$.

The particle $A$ is converted into $C$, $via$ following reaction.
$A \to B{ + _2}\mathrm{H}{\mathrm{e}^4}$
$B \to C\,\, + \,\,2{e^ - }$

The mass of radium (mass number 226, half-life 1600 years) with an activity of one curie is almost?

The energy released in the explosion of an atom bomb is mainly due to

In the reaction
$_7{\mathrm{N}^{14}} + \alpha { \to _8}{X^{17}}{ + _1}{p^1}$
identify $X$.

Isotopes are atoms having

If a star can convert all the He nuclei completely into oxygen nuclei, the energy released per oxygen nuclei is ( Mass of the nucleus is $4.0026\;\,\,\mathrm{amu}$ and mass of oxygen nucleus is $15.9994\;\,\,\mathrm{amu}$)

The half-life of $A{u^{198}}$ is 2.7 days. The activity of 1.50 mg of $A{u^{198}}$ if its atomic weight is $198\,g\,mo{l^{ - 1}}$ is $\left( {{N_A}\, = \,6 \times {{10}^{23}}\,/\,mol} \right)$