Physics · Science General

Nuclear Physics and Energy

1,296 Questions

Access a comprehensive set of questions on nuclear physics, reactor mechanisms, and atomic energy. Topics include nuclear fission, plasma generation, and radiation control. These physics questions form a core part of the syllabus for various engineering and civil service exams.

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Nuclear Physics and Energy Questions

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Scientists are working hard to develop nuclear fusion reactor. Nuclei of heavy, $ _{ 1 }^{ 2 }{ H }$, known as deuteron and denoted by D, can be thought of as a candidate for fusion reactor. The D-D reaction is  $ _{ 1 }^{ 2 }{H }+ _{ 1 }^{ 2 }{ H }\rightarrow _{ 2 }^{ 3 }{ He+n+energy }$. In the core of fusion reactor, a gas of heavy hydrogen is fully ionized into deuteron nuclei and electrons.This collection of $ _{ 1 }^{ 2 }{ H }$ nuclei and electron is known as plasma. The nuclei move randomly in the reactor core and occasionally come close enough for nuclear fusion to take place. Usually, the temperatures in the reactor core plasma. Special techniques are used which confine the plasma for a time $\displaystyle { t } _{ 0 }$ before the particles fly away from the core. If $n$ is the density (number/volume) of deuterons, the product ${ nt } _{ 0 }$  is called Lawson number, In one of the criteria, a reactor is termed successful if Lawson number is greater than $5 \times { 10 }^{ 14}s/{ cm }^{3 }$. It may be helpful to use the following: Boltzmann constant 

$k=8.6\times { 10 }^{ -5 }eV/K$; $\displaystyle \frac { { e }^{ 2 } }{ 4\pi { \epsilon } _{ 0 } } =1.44\times { 10 }^{ -9 }eVm$. In the core of nuclear fusion reactor. the gas becomes plasma because of :

  1. strong nuclear force acting between the deuterons

  2. coulomb force acting between the deuterons

  3. coulomb force acting between deuteron-electron pairs

  4. the high temperature maintained inside the reactor core
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The temperature inside the core of nuclear reactor is so high that the gas of heavy hydrogen used becomes the fourth state of matter which we call as plasma.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Introduction of which rod in a nuclear reactor controls  chain reaction ?

  1. Iron rods

  2. Silicon rods

  3. Cadmium rods

  4. Platinum rods
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cadmium rods are used as control rods in nuclear reactors to control the fission rate of uranium and plutonium. These are capable of absorbing many neutrons without fissioning themselves. Composition of control rods is designed for the neutron spectrum of the reactor. Rods are composed of boron,silver,indium and cadmium which can absorb excess neutrons.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Nuclear reactors are normally refuelled ___________.

  1. when they are decommissioned

  2. when the gauge indicates fuel low
  3. in every $12$ to $18$ months
  4. in every $2$ to $4$ weeks
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nuclear power plants rum almost all the time and refuel only once every two years or so. Outages typically occur in the spring or autumn when electricity demand is lowest and there is little winter heating or summer air conditioning.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

The functions of the reflectors in nuclear power plant is that:

  1. It reflects the neutrons that are escaping from the case.

  2. It reflects the radiation escaping the case of the reactor.
  3. Both $(1)$ and $(2)$

  4. It accelerates the reaction.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both (1) and (2)

A reflector is a region of unfueled material surrounding the core . Its function is to scatter neutrons that leak from the core, thereby returning some of them back into the core. This design feature allows for a smaller core size. In addition, reflectors "smooth out" the power density by utilizing neutrons that would otherwise leak out through fissioning within fuel material located near the core's outer region.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Nuclear power plants always operates as ___________.

  1. peak load plants

  2. base load plants

  3. can be used as both; the load and peak load plants depends on the requirements

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Base load power plants operate at maximum output. They shut down or reduce power only to perform maintainance or repair. Base load power plants include coal, fuel oil, almost all nuclear, geothermal, hydroelectric, biomass and combined cycle matural gas plants.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Which of the reactors are highly stable?

  1. Pressurised water reactors

  2. Boiling water reactors

  3. Pressurised heavy water reactors

  4. Fast breeder reactors
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Boiling Water Reactors (BWR) are generally considered highly stable due to the negative void coefficient, where increased steam production reduces reactivity, providing an inherent safety mechanism.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Which of the following is NOT used as a nuclear fuel?

  1. $U-232$
  2. $Th-232$
  3. $C1-241$
  4. $U-236$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Common nuclear fuels include U-235, U-238, Th-232, and Pu-239/241. U-232 is a decay product, Th-232 is fertile (can become fuel), and C1-241 (likely Pu-241) is a fuel. U-236 is a stable decay product of U-235 fission, not used as fuel.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

The pressurised water reactor $(PWR)$ employs:

  1. Light water and natural uranium

  2. Heavy water and enriched uranium

  3. Light water and enriched uranium

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pressurized Water Reactors (PWR) use light water as both coolant and moderator, and require enriched uranium (typically 3-5% U-235) to sustain the chain reaction.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

The nuclear reactor at Kaiga is a :

  1. research reactor

  2. fusion reactor

  3. breedor reactor

  4. power reactor
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nuclear reactor at Kaiga is Kaiga Atomic Power Station.

A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity. 
The use of nuclear reactor for electricity and power generation classifies it as a power reactor.

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

Nuclear power reactor is based on the principle of.

  1. Exothermic chemical reactions

  2. Endothermic chemical reactions

  3. Controlled nuclear fission

  4. Thermonuclear fusion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Controlled nuclear fission 

In a nuclear power reactor, materials that may undergo nuclear fission is used in a controlled manner to produce a steady state supply of heat. 

Multiple choice chemistry nuclear physics nuclear reactor the nuclear power station isotopes and nuclear chemistry

A nuclear reactor must consist of which of the following parts?
I. Electric generator
II. Fissionable fuel elements
III. Moderator

  1. I only

  2. III only

  3. I and II only

  4. II and III only

  5. I, II and III
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A nuclear reactor must consist:
 II. Fissionable fuel elements such as U-235 and Pu-239.
III. Moderator (heavy water) which slows down the speed of neutrons.