April 24 2025 Current Affairs MCQs

Explanation

Both Statement-I and Statement-II are correct, and Statement-II is not the correct explanation for Statement-I

• Giant Low Surface Brightness (GLSB) Galaxies are a rare and massive class of spiral galaxies characterised by extremely diffuse stellar disks. Despite its vast size and rich hydrogen content, it exhibits very low surface brightness. Hence, it is hard to detect.
• Typically embedded within large halos of dark matter, especially in the outer regions and neutral hydrogen gas(HI), the raw material for star formation.
• Show flat or slowly rising rotation curves, consistent with massive, extended dark matter halos.
• Often host smaller and less evolved central black holes than other galaxies of similar size.

Answer: (b) Both Statement-I and Statement-II are correct, and Statement-II is not the correct explanation for Statement-I; Difficulty Level: Hard

Explanation

All statements are correct

• Fast Breeder Reactors (FBRs) are advanced nuclear reactors designed to generate more fissile material than they consume, effectively “breeding” fuel as they operate.
• They use fast (high-energy) neutrons instead of slow (thermal) neutrons, and typically employ a mixture of uranium and plutonium as fuel.
• Instead of moderator, liquid sodium is commonly used as a coolant to maintain fast neutron spectrum.
• The core is surrounded by a “breeder blanket” of fertile material (like uranium-238), which absorbs excess neutrons and is converted into fissile plutonium-239, creating more fuel for future use.
  • Making FBRS highly efficient in utilising nuclear fuel resources compared to conventional reactors.

Answer: (d) 1, 2 and 3; Difficulty Level: Medium

Explanation

Statements 1 and 2 are correct

• A lipid is a water-insoluble organic compound. They include fats, waxes, oils, hormones, etc.

Statement 3 is incorrect

• Oxygen, carbon, and hydrogen atoms combine to form lipids through chemical bonding. Lipids make up about 30% of a cell’s dry weight.

Statement 4 is correct

• They’re part of cell membranes and help control what goes in and out of your cells. They help move and store energy, absorb vitamins, and make hormones.
• The functions of lipids also include:
  • Triglycerides: Transport and store energy.
  • Steroid Hormones: Send messages in cells.
  • Bile salts from cholesterol help digest fat.
  • Fatty Acids: Metabolise to create energy.
  • Phospholipids are like gatekeepers that let some molecules into your cells but require others to come in with proteins.
  • Cholesterol: Building cell membranes, producing hormones like vitamin D, aiding digestion, etc.

Answer: (a) Only one; Difficulty Level: Hard

Explanation

Statement 1 and 3 are correct

• Cabinet Committees are high-level, extra-constitutional bodies (not mentioned in the Constitution), formed to streamline decision-making and reduce the Cabinet’s workload by focusing on specific policy areas like security, economic affairs, and appointments.
• There are eight cabinet committees:
  • Appointments Committee of the Cabinet
  • Cabinet Committee on Accommodation
  • Cabinet Committee on Economic Affairs
  • Cabinet Committee on Parliamentary Affairs
  • Cabinet Committee on Political Affairs
  • Cabinet Committee on Security
  • Cabinet Committee on Investment and Growth
  • Cabinet Committee on Employment and Skill Development
• Except for the Cabinet Committee on Parliamentary Affairs, chaired by the Minister of Parliamentary Affairs and the Cabinet Committee on Accommodation (CCA), chaired by the Home Minister, all other cabinet committees are chaired by the Prime Minister.

Answer: (a) 1 and 3; Difficulty Level: Easy

Explanation

Statement 1 is incorrect

• Hydrogen-Based Explosive:
  • Utilizes Magnesium hydride (MgH₂) instead of nuclear fusion/fission.
  • Weighs only 2 kg—compact, tactical, and portable.
  • Working mechanism:
    • Initiated via thermal decomposition of MgH₂ by a conventional explosive.
    • Releases hydrogen gas, which ignites upon mixing with air, forming a high-temperature fireball.
    • Produces temperatures >1000°C, much higher than Trinitrotoluene’s (TNT) blast force.
    • Generates sustained combustion instead of a short-lived shockwave.
    • Delivers 428.43 kilopascals peak overpressure at 2 meters—about 40% of TNT’s pressure.

Statement 2 is correct

• Combustion sustains for over 2 seconds, enhancing area impact and heat damage.
• Capable of burning through materials like aluminium alloys — key for infrastructure targeting.
• Uses a novel “one-pot synthesis” to enhance safety and cost-efficiency.

Answer: (b) 2 only; Difficulty Level: Hard

Explanation

Option (a) is correct, but option (b) is incorrect

• Dark matter:
  • It is an invisible, mysterious substance making up about 27% of the universe.
  • It doesn’t emit or interact with light, making it detectable only through its gravitational effects on visible matter.

Options (c) and (d) are incorrect

• Key features:
  • Invisible: Does not emit or reflect light.
  • Gravitational influence: Exerts gravitational pull, affecting galaxy rotation and large-scale structure.
  • Non-baryonic: Not made of the same particles as normal matter (protons, neutrons). Cold and Slow-Moving Particles move slowly, allowing clumping into large halos around galaxies.
  • Galaxy formation: Dark matter acts as a gravitational scaffold, aiding galaxy and star formation.
  • Cosmic structure: Influences the distribution of galaxies and forms the cosmic web.
  • Refining Models: Vital in cosmological simulations, helping scientists understand universe formation.

Answer: (a) It is a mysterious substance making up about 27% of the universe; Difficulty Level: Hard

Explanation

Statements 1, 3 and 4 are correct

• Heatwave is considered if the maximum temperature of a station reaches at least 40˚C or more for Plains and at least 30˚C or more for Hilly regions.
• Favourable conditions for Heatwave:
  • Transportation/Prevalence of hot dry air over a region (There should be a region of warm dry air and appropriate flow pattern for transporting hot air over the region).
  • The sky should be practically cloudless (To allow maximum insulation over the region).
  • Large amplitude anti-cyclonic flow over the area.

Statement 2 is incorrect

• Absence of moisture in the upper atmosphere (As the presence of moisture restricts the temperature rise).

Answer: (c) Only three; Difficulty Level: Medium