Which Indian act provides for the payment of compensation in the event of a nuclear accident?
- Disaster Management Act
- Atomic Energy Act
- Environment Protection Act
- Civil Liability Act
Explanation: The Civil Liability for Nuclear Damage Act (2010) establishes a no-fault liability regime for nuclear operators in India.
What is the primary technical barrier for achieving controlled nuclear fusion on Earth?
- Waste disposal
- Fuel scarcity
- Plasma confinement
- Neutron shortage
Explanation: Maintaining plasma at extreme temperatures (millions of degrees) requires advanced magnetic or inertial confinement to prevent it from touching vessel walls.
Which specific 'Stage' of India's nuclear program involves the use of Thorium blankets in Fast Breeder Reactors?
- Stage Three
- Stage Two
- Stage Four
- Stage One
Explanation: In Stage 2, Thorium-232 is placed in the 'blanket' of Fast Breeder Reactors to be converted into fissile Uranium-233 for Stage 3.
Which particle is used as a 'projectile' to bombard a heavy nucleus to trigger nuclear fission?
- Positron
- Electron
- Neutron
- Proton
Explanation: Neutrons are ideal because they carry no charge, allowing them to penetrate the positively charged nucleus easily.
What is the primary function of control rods in a nuclear reactor?
- Absorbing neutrons
- Moderating speed
- Cooling fuel
- Reflecting neutrons
Explanation: Control rods, made of materials like Boron or Cadmium, are inserted into the core to absorb neutrons and manage the rate of fission.
Which material is utilized as both a moderator and a coolant in India's fleet of Pressurized Heavy Water Reactors (PHWRs)?
- Heavy water
- Graphite blocks
- Light water
- Liquid sodium
Explanation: PHWRs use Deuterium Oxide (Heavy Water) to slow down neutrons and carry away heat from the reactor core.
The 'Z-backscatter' technology used in high-security scanners at airports utilizes which form of radiation?
- Ultrasound
- Infrared
- Microwaves
- X-rays
Explanation: Z-backscatter technology uses low-energy X-rays to detect hidden objects by analyzing the radiation reflected back from the target.
The 'PUREX' process in the nuclear fuel cycle is primarily used for:
- Spent fuel reprocessing
- Heavy water production
- Reactor cooling
- Isotope enrichment
Explanation: Plutonium Uranium Reduction Extraction (PUREX) is the standard method for extracting uranium and plutonium from spent nuclear fuel.
The 'Nuclear Suppliers Group' (NSG) was formed in 1974 primarily as a response to which event?
- Chernobyl disaster
- Suez Crisis
- India's nuclear test
- NPT signing
Explanation: The NSG (London Club) was formed after India's 'Smiling Buddha' test to prevent the diversion of civilian nuclear tech for weapons.
What is the approximate 'half-life' of Plutonium-239, a key material in nuclear fuel and weapons?
- Ten million years
- Hundred years
- Twenty-four thousand years
- Five years
Explanation: Pu-239 has a long half-life of approximately 24,100 years, necessitating extremely long-term waste management.
The 'Fast Breeder Test Reactor' (FBTR) at Kalpakkam uses which substance as a coolant?
- Helium gas
- Liquid sodium
- Carbon dioxide
- Heavy water
Explanation: Fast Breeder Reactors use liquid metals like sodium because they do not slow down neutrons, which is essential for breeding fuel.
Which Indian nuclear power plant is the first to be built with Russian collaboration using VVER-1000 reactors?
- Tarapur
- Kaikas
- Narora
- Kudankulam
Explanation: Kudankulam in Tamil Nadu utilizes Russian-designed VVER (Water-Water Energetic Reactor) technology.
Which form of radiation is most effective for the 'Food Irradiation' process to prevent spoilage and kill pests?
- Ultraviolet
- Gamma radiation
- Microwave
- Alpha radiation
Explanation: Gamma rays (often from Cobalt-60) are used to sterilize food by killing bacteria and parasites without making the food radioactive.
The 'India-US Civil Nuclear Deal' (2008) is officially known as which agreement?
- The NPT Waiver
- The NSG Protocol
- The 123 Agreement
- The Hyde Act
Explanation: Named after Section 123 of the US Atomic Energy Act, it provided India a unique exception to trade in nuclear fuel and technology.
The 'Radura' symbol on food packaging indicates that the food has undergone:
- Gamma irradiation
- Vacuum sealing
- Chemical washing
- Genetic modification
Explanation: The Radura is the international symbol for irradiated food, used to extend shelf life and ensure food safety.
Which emission from radioactive substances is characterized by being an electromagnetic wave of very high frequency?
- Beta particles
- Gamma rays
- Neutron flux
- Alpha particles
Explanation: Gamma rays are high-energy photons (electromagnetic radiation) with high penetrating power.
Which radioactive particle is identical in mass and charge to a Helium-4 nucleus?
- Gamma photon
- Positron emission
- Beta particle
- Alpha particle
Explanation: An alpha particle consists of two protons and two neutrons, making it identical to a helium nucleus (He-4).
In the context of nuclear security, what does the term 'Dirty Bomb' refer to?
- Radiological dispersal device
- Underground fission test
- Small nuclear weapon
- Liquid waste spill
Explanation: A dirty bomb uses conventional explosives to scatter radioactive material over a wide area, causing radiological contamination rather than a nuclear blast.
What is the function of the 'Biological Shield' in a nuclear power plant?
- Enriches the uranium
- Kills harmful bacteria
- Cools the reactor
- Protects from radiation
Explanation: The biological shield, usually a thick concrete wall, absorbs gamma rays and neutrons to protect the plant workers and the environment.
Which substance is used as a 'Cryogen' to cool the superconducting magnets in fusion reactors like ITER?
- Heavy Water
- Solid Carbon
- Liquid Helium
- Liquid Nitrogen
Explanation: Liquid Helium is used to reach temperatures near absolute zero, which is necessary for the magnets to achieve superconductivity.
Which chemical element is the end-product of the natural decay series of Uranium-238?
- Radon
- Radium
- Lead
- Thorium
Explanation: All natural radioactive decay series (Uranium, Thorium) eventually terminate at stable isotopes of Lead.
The 'Yellowcake' trade in international diplomacy refers to the processed form of:
- Plutonium pellets
- Thorium concentrate
- Enriched fuel
- Uranium oxide
Explanation: Yellowcake is a type of uranium concentrate powder obtained from leach solutions, representing an intermediate step in fuel processing.
Which specific chemical process is most commonly used in India for the production of heavy water?
- Vitrification
- Centrifugation
- Purex process
- Girdler-Sulphide process
Explanation: The Girdler-Sulphide (GS) process involves an exchange of isotopes between water and hydrogen sulphide gas, used at several Indian heavy water plants.
What is the primary advantage of 'Vitrification' in radioactive waste management?
- Reduces half-life
- Solidifies liquid waste
- Generates electricity
- Eliminates radiation
Explanation: Vitrification turns highly radioactive liquid waste into a stable, non-leachable glass form suitable for long-term geological disposal.
In nuclear physics, what is the primary role of a 'Moderator'?
- Accelerate neutrons
- Generate neutrons
- Stop neutrons
- Slow down neutrons
Explanation: A moderator slows down fast-moving neutrons to thermal speeds, increasing the likelihood of further fission in U-235.
Which byproduct of nuclear reactors is the most significant concern for long-term 'High-Level Waste' disposal?
- Tritium gas
- Cobalt isotopes
- Nitrogen-16
- Minor actinides
Explanation: Actinides (like Americium, Curium, Neptunium) remain radioactive for thousands of years and are the primary contributors to long-term waste toxicity.
Which radioactive isotope is utilized in the process of 'Carbon Dating' to determine the age of organic artifacts?
- Carbon-13
- Carbon-14
- Carbon-11
- Carbon-12
Explanation: Carbon-14 is a radioactive isotope that decays at a known rate, allowing scientists to date organic materials up to 50,000 years old.
The process of 'Enrichment' specifically involves increasing the concentration of which isotope in Uranium?
- Uranium-233
- Uranium-232
- Uranium-238
- Uranium-235
Explanation: Enrichment increases the percentage of U-235 in fuel to make it suitable for nuclear reactors or weapons.
Which nuclear fusion fuel combination is considered the most feasible for first-generation fusion reactors like ITER?
- Proton and Electron
- Deuterium and Tritium
- Uranium and Plutonium
- Helium and Carbon
Explanation: The D-T reaction has the lowest ignition temperature and the highest energy yield compared to other fusion fuel pairs.
In the second stage of India's nuclear program, 'breeding' refers to the creation of more fuel than is consumed. Which fuel is produced?
- Thorium-232
- Plutonium-239
- Uranium-238
- Uranium-235
Explanation: Fast Breeder Reactors (Stage 2) convert U-238 into fissile Plutonium-239.
The 'Kamini' reactor at Kalpakkam is significant because it is the world's only experimental reactor using:
- Uranium-235
- Thorium-232
- Plutonium-238
- Uranium-233
Explanation: Kamini is a 30 kW research reactor that uses Uranium-233 fuel derived from the irradiation of thorium.
India's 'Global Centre for Nuclear Energy Partnership' (GCNEP), a hub for nuclear security research, is located in:
- Maharashtra State
- Karnataka State
- Gujarat State
- Haryana State
Explanation: GCNEP is situated in Bahadurgarh, Haryana, and focuses on nuclear security, safety, and non-proliferation studies.
Which specific property determines the 'Half-life' of a radioactive substance?
- External temperature
- Chemical bonding
- Intrinsic decay rate
- Ambient pressure
Explanation: Radioactive decay is a random atomic process unaffected by external physical or chemical conditions.
Which type of radiation has the lowest penetrating power and can be stopped by a simple sheet of paper?
- Gamma rays
- Alpha particles
- X-ray flux
- Beta particles
Explanation: Alpha particles are relatively large and heavy; their high charge makes them interact strongly with matter, stopping quickly.
The 'International Thermonuclear Experimental Reactor' (ITER) project in France aims to demonstrate the feasibility of:
- Thorium cycling
- Nuclear fusion
- Fast fission
- Waste vitrification
Explanation: ITER is a global collaboration to prove that nuclear fusion—the process that powers the sun—can be a viable source of energy.
What happens to the mass of the nucleus during a nuclear fission reaction?
- Mass increases
- Mass decreases
- Mass fluctuates
- Mass stays same
Explanation: In fission, the total mass of the products is less than the original mass; the 'missing mass' is converted into energy ($E=mc^2$).
Which Indian research reactor was the first to use 'Uranium-233' as fuel, demonstrating the feasibility of the third stage?
- Dhruva
- Zelina
- Kamini
- Purnima
Explanation: Kamini (Kalpakkam Mini reactor) is the first and only reactor in the world specifically designed to operate on U-233 fuel.
Which radioactive isotope is utilized as a source of high-energy gamma rays for industrial radiography?
- Thorium-232
- Carbon-14
- Uranium-238
- Cobalt-60
Explanation: Cobalt-60 is a prolific gamma emitter used in medical radiotherapy and for inspecting structural defects in industrial metals.
Which international body is responsible for the 'Safeguards' mechanism to ensure nuclear energy is used for peaceful purposes?
Explanation: The International Atomic Energy Agency (IAEA) inspects nuclear facilities to verify that states are not diverting materials for weapons.
Which specialized device is used in nuclear fusion research to confine plasma using powerful magnetic fields?
- Tokamak
- Spectrometer
- Cyclotron
- Calandria
Explanation: A Tokamak is a torus-shaped device that uses magnetic confinement to stabilize and heat plasma for fusion reactions.
India's first nuclear reactor, 'Apsara', was commissioned in 1956. What type of reactor was it?
- Fusion reactor
- Pressurized reactor
- Pool-type reactor
- Breeder reactor
Explanation: Apsara was a swimming-pool-type research reactor built with assistance from the United Kingdom.
Which radioisotope is used in 'Smoke Detectors' to ionize air and detect particles?
- Strontium-90
- Radon-222
- Americium-241
- Plutonium-239
Explanation: Americium-241 emits alpha particles that ionize the air in a chamber; smoke disrupts this current, triggering the alarm.
What is the term for the minimum amount of fissile material required to maintain a self-sustaining nuclear chain reaction?
- Subcritical mass
- Stable mass
- Critical mass
- Binding mass
Explanation: Critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction.
Which specific isotope is predominantly found in natural Uranium, making up over 99% of its composition?
- Uranium-234
- Uranium-235
- Uranium-233
- Uranium-238
Explanation: Natural uranium consists of approximately 99.3% U-238 and only 0.7% of the fissile U-235 isotope.
Which organization within the Department of Atomic Energy is responsible for mining and processing Uranium in India?
Explanation: Uranium Corporation of India Limited (UCIL) manages all uranium mining and processing activities, primarily in Jaduguda, Jharkhand.
In a nuclear reactor, the term 'Cladding' refers to the protective layer surrounding the fuel, usually made of:
- Tungsten steel
- Zirconium alloy
- High-grade lead
- Enriched graphite
Explanation: Zircaloy (Zirconium alloy) is used because of its low absorption cross-section for thermal neutrons and high corrosion resistance.
Which mineral found in the monazite sands of Kerala is the primary source of Thorium?
- Rutile
- Ilmenite
- Monazite
- Pitchblende
Explanation: Monazite is a reddish-brown phosphate mineral that contains rare-earth metals and significant amounts of thorium.
In the context of India's three-stage nuclear power program, what is the primary fuel for the third stage?
- Thorium-232
- Plutonium-239
- Natural Uranium
- Enriched Uranium
Explanation: The third stage is designed to utilize India's vast thorium reserves by converting Thorium-232 into fissile Uranium-233.
What is the primary radioactive waste management technique involving the trapping of waste in glass blocks?
- Vitrification
- Fractionation
- Dilution
- Incineration
Explanation: Vitrification is the process of mixing high-level liquid waste with glass-forming materials to create a stable, solid waste form.
What is the SI unit for measuring the activity of a radioactive source?
- Roentgen
- Sievert
- Gray
- Becquerel
Explanation: The Becquerel (Bq) measures the rate of radioactive decay (one decay per second).
Which Indian city serves as the headquarters of the Bhabha Atomic Research Centre (BARC)?
- Trombay Mumbai
- Chennai City
- Hyderabad City
- New Delhi
Explanation: BARC, India's premier nuclear research facility, was founded by Homi J. Bhabha in Trombay, Mumbai.
Which nuclear technology is being promoted as a 'Small Modular Reactor' (SMR) for flexible power generation?
- Micro fission
- Fusion cores
- Factory-built units
- Open cycle
Explanation: SMRs are advanced nuclear reactors with power capacity up to 300 MW, designed to be built in factories and transported to sites.
What is the primary advantage of a 'Fast' reactor over a 'Thermal' reactor?
- Higher fuel efficiency
- Low temperature
- Zero waste produced
- No fuel needed
Explanation: Fast reactors can extract 60–70 times more energy from uranium by 'breeding' fuel and burning long-lived actinides.
In nuclear physics, 'Ionizing Radiation' is defined as radiation with enough energy to:
- Remove bound electrons
- Split heavy nuclei
- Heat up water
- Create visible light
Explanation: Ionizing radiation (like Alpha, Beta, X-rays) has sufficient energy to detach electrons from atoms, creating ions.
Which radioisotope is commonly used in medical diagnostics for the study of thyroid gland functions?
- Iodine-131
- Sodium-24
- Cobalt-60
- Carbon-14
Explanation: Iodine-131 is used in nuclear medicine for both diagnosing and treating conditions related to the thyroid gland.
Which term describes a nuclear reactor that is operating such that the number of neutrons remains constant over time?
- Supercritical state
- Steady state
- Critical state
- Subcritical state
Explanation: In a critical state, the 'effective neutron multiplication factor' (k) is exactly 1, meaning the chain reaction is self-sustaining and stable.
Which Indian scientist is widely regarded as the 'Architect' of India's three-stage nuclear power program?
- Satish Dhawan
- Homi J. Bhabha
- APJ Abdul Kalam
- Vikram Sarabhai
Explanation: Dr. Homi Jehangir Bhabha envisioned a strategic path using India's limited uranium and abundant thorium to achieve energy independence.
The 'Chernobyl' nuclear disaster in 1986 was primarily caused by a catastrophic failure in which type of reactor?
- PHWR reactor
- RBMK reactor
- CANDU reactor
- VVER reactor
Explanation: The RBMK design had a 'positive void coefficient,' which caused a power surge during a low-power safety test.
Which Indian organization is the nodal agency for the regulation of nuclear safety and radiation protection?
Explanation: The Atomic Energy Regulatory Board (AERB) frames safety policies and monitors all nuclear-related activities in India.
Which international treaty prohibits all nuclear explosions, for both civilian and military purposes, in all environments?
- The CTBT
- The MTCR
- The ABM Treaty
- The NPT
Explanation: The Comprehensive Nuclear-Test-Ban Treaty (CTBT) aims to ban all nuclear testing. India, although not a signatory, maintains a voluntary moratorium.