Controlled Nuclear Reaction

Q.

Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of (a) and (b).

Given = 226.02540 u, = 222.01750 u,

= 220.01137 u, = 216.00189 u.

Q. On fission of one nucleus of $U^{235}$, the amount of energy obtained is $200MeV$. The power obtained in a reactor is $1000kW$. Number of nuclei fissioned per second in the reactor is

1. $3.125\times {10}^{16}$
2. $6.25\times {10}^{10}$
3. $6.25\times {10}^{20}$
4. $3.125\times {10}^{32}$

Q. Assume that the nuclear binding energy per nucleon $\left(B/A\right)$ versus mass number $\left(A\right)$ is as shown in the figure. Use this plot to choose the correct choice(s) given below.

1. Fusion of two nuclei with mass numbers lying in the range of $1<A<50$ will release energy.
2. Fusion of two nuclei with mass numbers lying in the range of $51<A<100$ will release energy.
3. Fission of a nucleus lying in the mass range of $100<A<200$ will release energy when broken into two equal fragments.
4. Fission of a nucleus lying in the mass range of $200<A<260$ will release energy when broken into two equal fragments.

Q.

How energy is released in nuclear fusion?

Q. A atomic power reactor furnace can deliver 300 MW. The energy released due to fission of each of uranium atom $U^{238}$ is 170 MeV. The number of uranium atoms fission per hour will be

1. $5\times {10}^{15}$
   
2. $10\times {10}^{22}$
   
3. $40\times {10}^{21}$
   
4. $30\times {10}^{25}$

Q. Cadmium rods are used as moderators in a nuclear reactor.

1. True
2. False

Q. Cadmium and Boron rods are used in a nuclear reactor to

1. Slow down the neutrons
2. Absorb excess number of thermal neutrons
3. Speed up neutrons
4. Absorb fast neutrons

Q. A sample of monatomic hydrogen gas contains 100 atoms and all the atoms are in nth excited state.As the atoms come down to the ground state following various transitions, they release a total energy of $\frac{4800}{49}Rch$. (where, 1Rch = 13.6 eV). Find the value of N, where maximum possible number of photons emitted in the process is 7N $\times$ 100. ___

Q. Which of the following statements are true regarding a nuclear reactor?

1. It uses control rods usually made of cadmium to regulate the energy generation.
2. It uses moderators to slow down the neutrons while generating the energy.
3. None of the above.
4. Moderators like heavy water, are used to cool down the reactor, during the fission reaction.

Q. Nuclear power stations are usually located near source of water because.

1. Fuel could be transported to the station by ships
2. Chemical wastes are discharged into the river
3. Water is used as coolant and moderator
4. Water is used to rotate the turbines of the generator

Q. A nuclear reactor has a power of $16KW$.If the energy per fission is $200MeV$, the number of fissions per second is

1. 5 x 10${}^{16}$
2. 5 x 10${}^{17}$
3. 5 x 10${}^{14}$
4. 5 x 10${}^{15}$

Q. A disadvantage of nuclear power is -

1. it produces carbon dioxide which is responsible for global warming
2. it produces toxic waste
3. it affects the ozone layer
4. it requires large amounts of fuel to produce a small amount of energy

Q.

What is a Geiger counter? Mention its signifi­cance.

Q. Boron rods, in a nuclear reactor, are used as.

1. moderator
2. Protective shield
3. Coolants
4. Control rods

Q. Consider the following nuclear reaction:
$X^{200}\to A^{110}+B^{90}+Energy$
If the binding energy per nucleon for $X$, $A$ and $B$ are $7.4MeV$, $8.2MeV$ and $8.2MeV$ respectively, the energy released will be:

1. $90MeV$
2. $110MeV$
3. $200MeV$
4. $160MeV$

Q. What, according to you, were the values displayed by Asha and her mother?

Q.

Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of (a) and (b).

Given = 226.02540 u, = 222.01750 u,

= 220.01137 u, = 216.00189 u.

Q. In a nuclear reactor, fission is produced in 1 g of ${}^{235}U\left(235.0349amu\right)$. In assuming that ${}_{53}^{92}Kr\left(91.8673amu\right)$ and ${}_{36}^{141}Ba\left(140.9139amu\right)$ are produced in all reactions and no energy is lost, calculate the total energy produced in kilowatt hour. Given: 1 amu $=931MeV$.

Q. In a nuclear reactor, nuclear energy is converted into _______.

Q. The rate of fission reaction of ${}_{92}{U}^{235}$ can be reduced by,

1. increasing the speed of the neutrons taking part in the reaction.
2. increasing the number of neutrons taking part in the reaction.
3. decreasing the number of neutrons taking part in the reaction.
4. decreasing the speed of the neutrons taking part in the reaction.

Q. Moderator is a substance that ..................... the neutrons in a nuclear reactor.

1. Slow down
2. Activates
3. Both (a) and (b) above
4. None of the above

Q. State two safety measures to be taken while establishing a nuclear power plant.

1. Use uranium rod and inside environment is not shielded
2. None of the above
3. Use uranium rod and inside environment should be shielded
4. Use copper rod and inside environment is not shielded

Q. A rate-meter measures the number of disintegrations per second from a radioactive source. It gives a count of $320$ counts per second. Ninety minutes later, it gives $40$ counts per second. The half life of the source is

1. $30mnts$
2. $45mnts$
3. $60mnts$
4. $75mnts$

Q. Assertion :Heavy water is 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.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q. Name a material which is used in making control rods in a nuclear reactor.

Q. Assertion (A): Binding energy per nucleon is the measure of the stability of the nucleus.

1. Both A and R are true and R is correct explanation of A.
2. A is true but R is false
3. A is false but R is true
4. Both A and R are true and R is not the correct explanation of A.

Q.

The principle of electromagnetic induction is used in which of the following phenomenon

1. Generation of electricity from wind energy.

2. Generation of electricity in thermal power plant.

3. Generation of electricity in nuclear power plant.

4. Generation of electricity in hydroelectricity

Q. If power of nuclear reactor is $100$ watt then rate of nuclear fission is:-

1. $3.6\times {10}^6$ per second
2. $3.2\times {10}^{12}$ per second
3. $1.8\times {10}^{12}$ per second
4. $1.8\times {10}^6$ per second

Q. __________ are used to absorb the neutrons in a nuclear reactor.

Q. Assertion :Assertion : Electrons do not experience strong nuclear force. Reason: Reason : Strong nuclear force is charge - independent force.

1. If both assertion and reason are true and reason is the correct explanation of assertion
2. If both assertion and reason are true and reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If both assertion and reason are false.