Nuclear Fission

Q. Statement I : Nuclear fission is a spontaneous process i.e. there is no need of external energy supply for this to happen.
Statement II : In a nuclear fission reaction the rest mass energy of the parent nucleus is more than the combined rest mass energy of two daughter fragments and neutrons.

1. Both the statements are correct and statement II infers to statement I
2. Both the statements are correct but statement II doesn’t infer to statement I
3. Statement I is correct but statement II is incorrect
4. Statement II is correct but statement I is incorrect

Q.

The explosion of the atomic bomb takes place due to

1. Nuclear fission

2. Nuclear fusion

3. Scattering

4. Thermionic emission

Q. The binding energy per nucleon of ${}_1^{2}H$ and ${}_2^{4}He$ are $1.1MeV$ and $7.0MeV$ respectively. Energy released in the process ${}_1^{2}H{+}_1^{2}H{\to }_2^{4}He$ is

1. $23.6MeV$
2. $25.2MeV$
3. $16.6MeV$
4. $13.6MeV$

Q. In a fission reaction ${}_{92}^{236}U{\to }^{117}X{+}^{117}Y+n+n$, the binding energy per nucleon of X and Y is 8.5 MeV whereas of 236 U is 7.6 MeV. The total energy liberated will be about

1. 200 KeV
2. 2 MeV
3. 200 MeV
4. 2000 MeV

Q.

The control rod in a nuclear reactor is made of

1. Uranium

2. Cadmium

3. Graphite

4. Plutonium

Q. A nucleus of mass number 220 initially at rest emits an alpha particle. If the $Q$ value of the reaction is $5.5MeV$, then the kinetic energy of the alpha particle is

1. $6.5MeV$
2. $5.5MeV$
3. $5.4MeV$
4. $2.0MeV$

Q. A nuclear fission is given below
$A^{240}\to B^{100}+C^{140}+Q\left(\text{energy}\right)$.
Let binding energy per nucleon of nuclei $A,B$ and $C$ be $7.6\text{MeV},8.1\text{MeV}$ and $8.1\text{MeV}$ respectively. Value of $Q$ is : (Approximately)

1. $20\text{MeV}$
2. $220\text{MeV}$
3. $120\text{MeV}$
4. $240\text{MeV}$

Q. Uranium ores contain one radium $-226$ atoms for every $2.8\times {10}^6$ uranium $-238$ atoms. Calculate the half - life of ${}_{92}^{238}U$, given that the half - life of ${}_{88}^{226}Ra$ is 1600 years. (${}_{88}^{226}Ra$ is a decay product of ${}_{92}^{238}U$)

1. $1.75\times {10}^3\text{years}$
2. $1600\times \frac{238}{92}\text{years}$
3. $4.55\times {10}^9\text{years}$
4. $1600\text{years}$

Q.

In a fission reaction
${}_{92}^{238}U\to {}^{117}X{+}^{117}Y+n+n$
the binding energy per nucleon of X and Y is 8.5 MeV whereas that of ${}^{236}U$ is 7.6 MeV. The total energy liberated will be about

1. 200 keV

2. 2 Mev

3. 200 MeV

4. 2000 MeV

Q. The fission of a heavy nucleus gives, in general, two smaller nuclei, two or three neutrons, some $\beta$-particles and some $\gamma$ -radiation. It is always true that the nuclei produced

1. have a total rest-mass that is greater than that of the original nucleus
2. have large kinetic energeis that carry off the greater part of the energy released
3. travel in exactly opposite directions
4. have neutron-to-proton ratios that are too low for stability

Q. ${}_{26}^{56}Fe⟶2{(}_{13}^{28}Al)m_{Fe}=55.93494m_{Al}=27.98191$
Find Q value of reaction. Is fission energetically possible?

1. -27 MeV, Yes
2. 27 MeV, No
3. 15 MeV, Yes
4. -15 MeV, No

Q. The number of neutrons released when ${}_{92}^{235}U$ undergoes fission by absorbing ${}_0^{1}n$ and $\left({}_{56}^{144}Ba{+}_{36}^{89}Kr\right)$ are formed

1. $0$
2. $1$
3. $2$
4. $3$

Q.

In fission of one uranium-235 nucleus, the loss in mass is 0.2amu. Calculate the energy released.

1. 186.2 MeV

2. 182.6 MeV

3. 156.4 MeV

4. 189.1 MeV

Q.

In fission of one uranium-235 nucleus, the loss in mass is 0.2 amu. Calculate the energy released.

1. 186.2 MeV

2. 182.6 MeV

3. 156.4 MeV

4. 189.1 MeV