Science – GK Questions

Pitch depends on frequency (higher frequency = higher pitch). Amplitude determines loudness. Confusing these is a common exam trap. [[NCERT Physics Class 9]]

Autotrophs (e.g., plants, cyanobacteria) synthesize organic compounds from inorganic sources via photosynthesis/chemosynthesis. They form the base of food chains. Basic ecology concept. [[NCERT Biology Class 12]]

Diamond is an allotrope of carbon with tetrahedral sp³ hybridization, forming a rigid 3D network. This structure gives extreme hardness. Graphite is another carbon allotrope with different properties. [[NCERT Chemistry Class 11]]

While Bitcoin popularized blockchain, its applications include supply chain tracking, voting systems, healthcare records, and smart contracts. Decentralized ledger technology has broad utility. [[NITI Aayog Reports]]

When light moves from denser (e.g., glass) to rarer medium (e.g., air) at angle > critical angle, it reflects entirely back. Used in optical fibers, prisms. Fundamental optics principle. [[NCERT Physics Class 12]]

Pancreatic beta cells (in Islets of Langerhans) secrete insulin, which lowers blood glucose by facilitating cellular uptake. Deficiency causes diabetes mellitus. Key physiology concept. [[NCERT Biology Class 11]]

EDTA (ethylenediaminetetraacetate) is a hexadentate ligand, forming six coordinate bonds with metal ions. Used in chelation therapy and water softening. Important for advanced chemistry. [[NCERT Chemistry Class 12]]

The UN's 2030 Agenda has 17 SDGs with 169 targets addressing poverty, inequality, climate change, etc. India actively participates in SDG implementation. Crucial for current affairs. [[NITI Aayog SDG Reports, NCERT Geography Class 11]]

Candela (cd) is one of seven SI base units, measuring luminous intensity in a given direction. Lumen measures total luminous flux; lux measures illuminance. Important for photometry. [[NCERT Physics Class 11]]

In light-dependent reactions, water photolysis splits H₂O into O₂, protons, and electrons. The O₂ is released as byproduct. Confirmed by isotopic labeling experiments. [[NCERT Biology Class 11]]

Van't Hoff approximation states reaction rate roughly doubles per 10°C temperature increase. Arrhenius equation gives precise temperature dependence. Important for kinetics problems. [[NCERT Chemistry Class 12]]

Biogas (from anaerobic digestion of organic waste) contains 50-75% methane (CH₄), a clean fuel. Promoted under GOBAR-DHAN scheme for rural energy and waste management. [[MNRE Reports, NCERT Chemistry Class 11]]

Bernoulli's principle: in a flowing fluid, pressure decreases as speed increases (conservation of energy). Explains airplane lift, venturi effect. Common misconception in exams. [[NCERT Physics Class 11]]

B-cells (B-lymphocytes) differentiate into plasma cells that secrete antibodies specific to antigens. T-cells assist in cell-mediated immunity. Central to adaptive immune response. [[NCERT Biology Class 12]]

Calcination decomposes carbonate ores (e.g., ZnCO₃ → ZnO + CO₂) by heating in limited air. Roasting is for sulfide ores in excess air. Key step in metal extraction. [[NCERT Chemistry Class 12]]

PM2.5 particles are fine inhalable particles (≤2.5 μm) that penetrate deep into lungs, causing respiratory/cardiovascular issues. Monitored under National Air Quality Index. [[CPCB Reports, NCERT Geography Class 11]]

Einstein explained photoelectric effect using photons (light quanta), showing particle behavior. This contributed to quantum theory. Wave nature is shown by interference/diffraction. [[NCERT Physics Class 12]]

Synapse is the junction where neurotransmitters transmit signals from one neuron to another. Essential for understanding nerve impulse transmission and brain function. [[NCERT Biology Class 11]]

In galvanic (voltaic) cells: oxidation at anode (loss of e⁻), reduction at cathode (gain of e⁻). Mnemonic: 'AnOx RedCat'. Critical for electrochemistry problems. [[NCERT Chemistry Class 12]]

Mangalyaan (Mars Orbiter Mission) made India the first Asian nation to reach Mars orbit (2014). It studied Martian surface and atmosphere. Important for current affairs and science sections. [[ISRO Reports, NCERT Geography Class 11]]