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 general knowledge science & technology

Stars generate energy through ?

  1. Nuclear Fission

  2. Proton Acceleration

  3. Nuclear Fusion

  4. Neutron Acceleration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Stars generate energy through nuclear fusion, where lighter nuclei (primarily hydrogen) combine to form heavier nuclei (helium) in the star's core. This process releases enormous amounts of energy because the mass of the products is slightly less than the mass of the reactants - this 'missing' mass is converted to energy according to E=mc². Nuclear fission (splitting heavy nuclei) is not the primary energy source for stars.

Multiple choice softskills communication

Over 75 percent of the energy produced in France derives from nuclear power, while in Germany it is just over 33 percent.

  1. while in Germany it is just over 33 percent

  2. compared to Germany, which uses just over

  3. whereas nuclear power accounts for just over

  4. whereas just over 33 percent of the energy

  5. compared with the energy from nuclear power in
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The phrase 'whereas nuclear power accounts for' provides a clear and grammatically complete contrast to the first clause. The original 'it is' is slightly ambiguous, and the other options are either wordy or create incomplete comparisons.

Multiple choice softskills leadership

Over 75 percent of the energy produced in France derives from nuclear power, while in Germany it is just over 33 percent.

  1. compared with the energy from nuclear power in Germany, where it is just over 33 percent

  2. compared to Germany, which uses just over 33 percent

  3. whereas nuclear power accounts for just over 33 percent of the energy produced in Germany

  4. whereas just over 33 percent of the energy comes from nuclear power in Germany
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option provides a clear, parallel comparison between the two countries. Using 'whereas' establishes a strong contrast, and the phrase 'accounts for' is the most idiomatic way to describe the proportion of energy sources in a formal context.

Multiple choice

In a nuclear reactor, control rods are made of

  1. B

  2. Cd

  3. Both 1 and 2

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

 Control rods in nuclear reactors are commonly made of boron and cadmium because these two elements have the ability to absorb neutrons.

Multiple choice

The hulls of modern nuclear powered submarines differ from those of diesel powered ones because they are covered with a vibration absorbing anechoic coating instead of normal paint.

  1. because they are covered with a vibration absorbing anechoic coating instead of

  2. because of being covered with a vibration absorbing anechoic coating rather than

  3. the hulls of nuclear powered submarines being covered with a vibration absorbing anechoic coating instead of being coated with

  4. in that the hulls of nuclear powered submarines are covered with a vibration absorbing anechoic coating rather than

  5. in their being covered with a vibration absorbing anechoic coating instead of
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct. The option corrects the unidiomatic usage of 'differ because' by using 'in that' instead. The option also removes the error of pronoun ambiguity by substituting 'they', which could have meant either 'hulls of nuclear powered submarines' or 'hulls of diesel powered submarines', with the proper noun.

Multiple choice

Hydrogen bomb works on the principle of _____.

  1. nuclear fission

  2. nuclear explosion

  3. nuclear fusion

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hydrogen bombs (thermonuclear weapons) work on the principle of nuclear fusion, where light nuclei (like isotopes of hydrogen - deuterium and tritium) combine to form heavier nuclei, releasing enormous energy. This is the same process that powers the Sun and stars. A fission bomb is typically used as the trigger to create the extreme temperatures and pressures needed to initiate fusion.

Multiple choice

What is the use of graphite rod in an atomic reactor?

  1. As lubricant

  2. As fuel

  3. As a non-conducting layer inside the reactor

  4. To decrease the velocity of neutron

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Graphite rods in nuclear reactors serve as moderators - they slow down fast neutrons produced during fission to thermal energies, making them more likely to cause further fission reactions. Graphite is NOT used as fuel (uranium/plutonium are fuel), not as lubricant in this context, and it is a conductor, not an insulator.

Multiple choice

The nuclear reaction - 1H2 + 1H2

  1. Fission reaction

  2. Fusion reaction

  3. Chain reaction

  4. Thermal reaction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The reaction H² + H² involves two deuterium nuclei fusing together, which is a nuclear fusion reaction. Fission splits a heavy nucleus, chain reaction is sustained fission, and thermal reaction is vague and non-specific.

Multiple choice

Consider the following facts:

  1. An advanced heavy water reactor is an Indian design which has thorium as its core.
  2. It forms the 3rd stage of India's three-stage nuclear power programme slated to begin operations in 2016.

Which of the above is/are true?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The advanced heavy water reactor (AHWR) is the latest Indian design for a next generation nuclear reactor that will burn thorium in its fuel core. It is slated to form the third stage in India's three-stage fuel cycle plan. This phase of the fuel cycle plan is supposed to be built starting with a 300MW prototype in 2016.

Multiple choice

What does the unit 'Sievert' measure?

  1. Energy released in fission energy

  2. Energy released in fusion energy

  3. Biological effect of radiation

  4. Time derivative of radiation effects
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The sievert (symbol: Sv) is the International System of Units (SI) derived unit of equivalent radiation dose, effective dose, and committed dose. Quantities that are measured in sieverts are designed to represent the stochastic biological effects of ionizing radiation. This SI unit is named after Rolf Maximilian Sievert.

Multiple choice

Which of the following are used as moderators in Nuclear Reactors?

  1. Heavy water
  2. Graphite
  3. Beryllium

  1. 1 and 2

  2. 2 and 3

  3. 1 and 3

  4. All three
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Commonly used moderators include regular (light) water (roughly 75% of the world's reactors), solid graphite (20% of reactors) and heavy water (5% of reactors). Beryllium has also been used in some experimental types, and hydrocarbons have been suggested as another possibility.

Multiple choice

In which of the following devices are you likely to encounter an application of nuclear technology?

  1. Door bells
  2. Smoke detectors
  3. Ice breaker

  1. 1 and 2

  2. 2 and 3

  3. 1 and 3

  4. Only 2

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A smoke detector is a device that detects smoke, typically as an indicator of fire. In this device, we see one of the civilian applications of nuclear chemistry. An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters. Several technological advances were introduced into icebreaking technology over the years, but it was not until the introduction of nuclear power in the Soviet icebreaker Lenin in 1959 that icebreakers developed to their full potential.

Multiple choice

Which of the following features would you associate with a self-sustaining nuclear chain reaction?

  1. In which products are of comparable mass to fission nuclei.
  2. In which the average number of neutrons released per nuclear that bombard other nuclei is more than one.

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nuclear fission is the process of splitting a nucleus into roughly equal parts, and releasing energy and neutrons in the process. If these neutrons are captured by another unstable nucleus, they can fission as well, leading to a chain reaction. The average number of neutrons released per nucleus that go on to fission another nucleus is referred to as k. Values of k larger than 1 mean that the fission reaction is releasing more neutrons than it absorbs, and therefore is referred to as a self-sustaining chain reaction.

Multiple choice

There are two ways to achieve the temperature and pressure necessary for hydrogen fusion to take place. Which of the following processes does a tokamak nuclear reactor employ to achieve conditions of fusion?

  1. Magnetic Confinement
  2. Inertial Confinement

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Magnetic confinement uses magnetic and electric fields to heat and squeeze the hydrogen plasma.Microwaves, electricity and neutral particle beams from accelerators heat a stream of hydrogen gas. This heating turns the gas into plasma. This plasma gets squeezed by super-conducting magnets, thereby allowing fusion to occur. The most efficient shape for the magnetically confined plasma is a donut shape (toroid). A reactor of this shape is called a tokamak.The ITER project in France is using this method.