BPSC General Science for Prelims: 30-Marks Strategy, Physics, Chemistry & Biology Important MCQs
A master blueprint to score 26+ marks in General Science (30 Questions) in BPSC Prelims. Detailed breakdown of high-frequency topics in Physics, Chemistry, and Biology, NCERT Class 9-10 summaries, and standard formula lists.
1. The 30-Question Science Block: The Most Predictable Section in BPSC
General Science constitutes exactly 20% of the entire BPSC Preliminary paper (30 questions carrying 30 marks). Unlike current affairs or general humanities where questions can originate from infinite sources, BPSC science questions adhere strictly to Class 9 and 10 NCERT fundamentals.
Aspirants who systematically cover the three core branches consistently score 25 to 28 marks, transforming General Science into the ultimate prelims qualifying safety net.
2. Biology Master Checklist: Vitamins, Human Physiology & Diseases
Biology alone commands 14 to 16 of the 30 science questions in recent papers:
• Vitamins and Deficiency Diseases: Memorize chemical names and deficiency symptoms (Vitamin A / Retinol - Night Blindness; Vitamin B1 / Thiamine - Beriberi; Vitamin C / Ascorbic Acid - Scurvy; Vitamin D / Calciferol - Rickets; Vitamin K / Phylloquinone - Blood Clotting failure).
• Human Digestive & Circulatory System: Roles of Pepsin (proteins in stomach), Trypsin (pancreatic juice), Bile (emulsifies fats in liver/gallbladder). Heart chambers, RBC vs WBC lifespans, and universal donor (O negative) vs universal recipient (AB positive).
• Plant Physiology: Xylem (water and mineral transport) vs Phloem (photosynthetic food translocation). Plant hormones: Auxins (cell elongation), Gibberellins (stem growth), Abscisic Acid (stress hormone / dormancy), and Ethylene (fruit ripening).
3. Physics High-Yield Areas: Optics, Thermodynamics & SI Units
Physics accounts for 7 to 9 questions focusing on everyday phenomena:
• Optics: Total Internal Reflection (optical fibers, mirages, sparkling of diamonds). Concave mirrors (shaving mirrors, car headlights, dentist scopes) vs Convex mirrors (rear-view vehicle mirrors for wide field of view). Dispersion of light through prisms (VIBGYOR).
• Mechanics & Gravitation: Value of g at poles (maximum) vs equator (minimum) vs Earth center (zero). Archimedes principle, atmospheric pressure measurement using mercury barometer, and surface tension causing spherical raindrops.
• Sound & Thermodynamics: Sound cannot travel through a vacuum. Latent heat of vaporization vs fusion (why steam burns are more severe than boiling water at 100°C).
4. Chemistry Essentials: Common Ores, Acids, Bases & Polymers
Chemistry questions test commercial compounds, metallurgy, and industrial applications:
| Commercial / Common Name | Chemical Name | Chemical Formula | Key Industrial / Daily Use |
|---|---|---|---|
| Baking Soda | Sodium Bicarbonate | NaHCO₃ | Food leavening, fire extinguishers, antacid |
| Washing Soda | Sodium Carbonate Decahydrate | Na₂CO₃·10H₂O | Water softening, glass and paper manufacturing |
| Bleaching Powder | Calcium Hypochlorite | CaOCl₂ | Water disinfection, fabric bleaching, oxidizer |
| Plaster of Paris | Calcium Sulphate Hemihydrate | CaSO₄·½H₂O | Bone fracture casts, sculptures, false ceilings |
| Gypsum | Calcium Sulphate Dihydrate | CaSO₄·2H₂O | Retarding cement setting time, soil conditioning |
| Laughing Gas | Nitrous Oxide | N₂O | Medical anesthetic, rocket propellant oxidizer |
| Heavy Water | Deuterium Oxide | D₂O | Neutron moderator and coolant in nuclear reactors |
| Dry Ice | Solid Carbon Dioxide | CO₂ (solid) | Refrigeration, cloud seeding, theatrical smoke |
5. High-Frequency Scientific Discoveries & Inventions Checklist
• Penicillin: Discovered by Alexander Fleming (1928) from Penicillium notatum.
• DNA Double Helix: Model proposed by James Watson and Francis Crick (1953).
• Blood Groups: Discovered by Karl Landsteiner (1900), Rh factor identified in 1940.
• Theory of Natural Selection: Formulated by Charles Darwin in "On the Origin of Species" (1859).
• Photoelectric Effect: Explained by Albert Einstein (1905), for which he received the 1921 Nobel Prize in Physics (NOT for relativity!).