A moderator is used in nuclear reactor in order to: (CSS 2009 General Science & Ability Paper)

Accelerate the neutrons
Slow down the speed of the neutrons
Increase the number of electrons
Decrease the number of electrons

Nuclear energy is the energy released from the nucleus, or core of an atom, which is composed of protons and neutrons. Nuclear energy is produced in two ways: Nuclear Fission and Fusion.

Nuclear Fission

Nuclear Fission occurs when a neutron slams into a larger atom, forcing it to excite and split into two smaller atoms, also known as fission products. Further, this sets off a chain reaction when additional neutrons are released. Also, when an atom splits, it releases a tremendous amount of energy.

  • Since Uranium and Plutonium are easy to initiate and control, they are the most commonly used as fission fuels in nuclear power reactors.
  • The fission energy released in these reactors heats water into steam which generates carbon-free electricity by using steam to spin a turbine.

Nuclear Fusion

Nuclear Fusion

Nuclear fusion happens when two atoms collide to form a heavier atom, similar to how two hydrogen atoms fuse to form one helium atom. This is the same process that powers the sun and generates enormous amounts of energy—many times greater than fission.

Nuclear Reactor

Nuclear reactors are fundamentally large kettles that heat water to generate massive amounts of low-carbon electricity. They are available in a variety of sizes and shapes and can be powered by a variety of different fuels.

  • A nuclear reactor generates and regulates the release of energy by splitting the atoms of specific elements.
  • The energy released in a nuclear power reactor is used to generate steam, which is then used to generate electricity.

Components of Nuclear Reactor

  • Fuel: The fuel used in a nuclear power plant contains fissile atoms whose energy is extracted by fission. Uranium-235 is the most common fuel.
  • Control Rods: In a nuclear reactor, the chain reaction is constantly managed by means of control rods which are made from a material capable of absorbing neutrons. They can be dropped or pulled to maintain or increase the fission rate.
  • Moderator: Its role is to slow down the neutrons released during the fission reaction which can otherwise be too energetic to efficiently provoke other fission reactions.
  • Coolant: The heat released during fission must be transferred from the reactor core to the turbine and alternator. This role is guaranteed by the coolant, the fluid used to remove the heat generated by the nuclear fuel.
  • Steam Generator: These are large heat exchangers for transferring heat from one fluid to another, here from a high-pressure primary circuit in pressurised water reactors (PWR & PHWR) to a secondary circuit where water turns to steam.

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Related MCQs

  1. Mauwazatain mean? (CSS 2013 Islamic Studies Paper)

    • A Collection of Ahadith
    • Two specific Surah of Quran
    • A book of Jafferi Fiqh
    • A book of Hanafi Fiqh

    Submitted by: CSS Exam Desk Team

  2. Scribe of the Treaty of Hudaibiya? (CSS 2017 Islamic Studies Paper)

    • Hazrat umar(رضی اللّٰہ عنہ)
    • Hazrat Ali(کرم اللہ تعالٰی وجہہ الکریم)
    • Hazrat usman(رضی اللّٰہ عنہ)
    • None of these

    Submitted by: CSS Exam Desk Team

  3. Omar Khayyam was a? (CSS 2014 General Science & Ability Paper)

    • Poet
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    • Astronomer
    • All of these

    Submitted by: CSS Exam Desk Team

  4. Which Sahabi was died in the hands of the Holy Prophet (PBUH) in the battle of Uhad? (CSS 2010 Islamic Studies Paper)

    • Hazrat Haris-bin-Haris(رضی اللّٰہ عنہ)
    • Hazrat Haris-bin-Azima(رضی اللّٰہ عنہ)
    • Hazrat Haris-bin-Hassan(رضی اللّٰہ عنہ)
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    Submitted by: CSS Exam Desk Team

  5. The fuel used in rockets is? (CSS 2015 General Science & Ability Paper)

    • Liquid oxygen
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    • All of these

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  6. The SYNONYM of the word \"ENTOURAGE\" is? (CSS 1990 English Precis & Composition Paper)

    • Tourist
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    Submitted by: CSS Exam Desk Team

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    • 8 Zil hajj
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    Submitted by: CSS Exam Desk Team

  8. Operation Desert Shield was launched by US in? (CSS 2015 Current Affairs Paper)

    • 2 August 1990
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    • None of these

    Submitted by: CSS Exam Desk Team

  9. The ozone layer protects the earth from_____ sent by sun? (CSS 2016 General Science & Ability Paper)

    • Ultraviolet rays
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    Submitted by: CSS Exam Desk Team

  10. The SYNONYM of the word \"HOODWINK\" is? (CSS 2009 English Precis & Composition Paper)

    • Avoid
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    Submitted by: CSS Exam Desk Team

  11. The most prosperous members of the Global South, which have become important exporters andmarkets for the major industrialized countries, are known as? (CSS 2013 Current Affairs Paper)

    • Newly industrialized countries
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  13. Headquarters of ICJ? (CSS 2017 Current Affairs Paper)

    • Bern, Switzerland
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    • None of these

    Submitted by: CSS Exam Desk Team

  14. The SYNONYM of the word \"BULWARK\" is? (CSS 2014 English Precis & Composition Paper)

    • Confuse
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    Submitted by: CSS Exam Desk Team

  15. Anjuman-e-Himayat e Islam was founded in______? (CSS 2017 Pakistan Affairs Paper)

    • 1980
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    Submitted by: CSS Exam Desk Team

  16. The oldeest internet search engine among the following is? (CSS 2010 Current Affairs Paper)

    • Google
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    Submitted by: CSS Exam Desk Team

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    • Oxygen
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    Submitted by: CSS Exam Desk Team

  18. Mohenjo-daro and Harappa were discovered in? (CSS 2015 Pakistan Affairs Paper)

    • 1909
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    Submitted by: CSS Exam Desk Team

  19. Cobalt is a material which is? (CSS 2010 General Science & Ability Paper)

    • Strongly attracted by a magnet
    • Not attracted by a magnet
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    Submitted by: CSS Exam Desk Team

  20. The Silsilah-i-Chishtiyah was founded in sub Continent by whom? (CSS 2012 Pakistan Affairs Paper)

    • Kh. Bahaud Din Naqshbandi
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    • Sh. Bahaud Din Zakria
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    Submitted by: CSS Exam Desk Team

  21. which book is called old testament? (CSS 2010 Islamic Studies Paper)

    • zuboor
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    Submitted by: CSS Exam Desk Team

  22. Who had written the Treaty of Hudaybiyyah? (CSS 2022 Islamic Studies Paper)

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    Submitted by: CSS Exam Desk Team

  23. Yerevan is capital of which country? (CSS 2018 Current Affairs Paper)

    • Armenia
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    Submitted by: CSS Exam Desk Team

  24. Which organelle is called the powerhouse of the cell? (CSS 2020 General Science & Ability Paper)

    • Mitochondria
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    • None of these

    Submitted by: CSS Exam Desk Team

  25. How can we symbolically write the 0zone Gas? (CSS 2022 General Science & Ability Paper)

    • 02
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    Submitted by: CSS Exam Desk Team