A human body required the 0.01 Curie activity of radioactive substance after 24 hours. The half-life of radioactive is 6 hours. The maximum activity of a radioactive substance that can be injected will be: 
1.  0.08
2.  0.04
3.  0.16
4.  0.32

If the mass of the iron nucleus is \(55.85~\text{u}\) and \(\mathrm{A} = 56\), the nuclear density of the iron is:

The energy equivalent of \(1\) g of substance is:
1. \(8.3\times10^{13}~\text{J}\)
2. \(9\times10^{13}~\text{J}\)
3. \(7.7\times10^{13}~\text{J}\)
4. \(11\times10^{13}~\text{J}\)

We are given the following atomic masses:

${}_{92}{}^{238}\mathrm{U}$ = 238.05079 u, ${}_2{}^4\mathrm{He}$= 4.00260 u

${}_{90}{}^{234}\mathrm{Th}$ = 234.04363 u, ${}_1{}^1\mathrm{H}$= 1.00783 u

${}_{91}{}^{237}\mathrm{Pa}$= 237.05121 u

Here the symbol Pa is for the element protactinium (Z = 91).

The energy released during the alpha decay of ${}_{92}{}^{238}\mathrm{U}$ is:

1. 6.14 MeV 

2. 7.68 MeV 

3. 4.25 MeV

4. 5.01 MeV 

We are given the following atomic masses:

${}_{92}{}^{238}\mathrm{U}$ = 238.05079 u, ${}_2{}^4\mathrm{He}$= 4.00260 u

${}_{90}{}^{234}\mathrm{Th}$ = 234.04363 u, ${}_1{}^1\mathrm{H}$= 1.00783 u

${}_{91}{}^{237}\mathrm{Pa}$= 237.05121 u

Here the symbol Pa is for the element protactinium (Z = 91).

Then:

1. ${}_{92}{}^{238}\mathrm{U}$ can not spontaneously emit a proton.

2. ${}_{92}{}^{238}\mathrm{U}$ can spontaneously emit a proton.

3. The Q-value of the process is negative.

4. Both (1) and (3)

The energy required in \(\mathrm{MeV} / \mathrm{c}^2\) to separate \({ }_8^{16} \mathrm{O}\) into its constituents is:
(Given mass defect for \({ }_8^{16} \mathrm{O}=0.13691 \mathrm{u}\))
1. \(127.5\)
2. \(120.0\)
3. \(222.0\)
4. \(119.0\)

The half-life of ${}_{92}{}^{238}\mathrm{U}$ undergoing $\mathrm{\alpha }$-decay is $4.5\times {10}^9$ years. What is the activity of the 1g sample of ${}_{92}{}^{238}\mathrm{U}$?

1. $2.11\times {10}^4 Bq$

2. $3.12\times {10}^3 Bq$

3. $1.23\times {10}^4 Bq$

4. $2.38\times {10}^3 Bq$

Tritium has a half-life of 12.5 y undergoing beta decay. What fraction of a sample of pure tritium will remain undecayed after 25 y?
 

$1. \frac{1}{8}\mathrm{th}$
$2. \frac{1}{4}\mathrm{th}$
$3. \frac{1}{3}\mathrm{rd}$
$4. \frac{1}{5}\mathrm{th}$

Which one of the following is incorrect?

Graph given below shows the variation of binding energy per nucleon, E_bn as a function of mass number. For nuclei with mass number A such that, 30 < A < 170, E_bn is almost constant because nuclear forces are:

1. Short-ranged 

2. Medium-ranged

3. Long-ranged

4. None of the above