Science GK: The Easiest 15 Marks in Your Exam

Science is the most PREDICTABLE section in GK. No opinions to confuse you, no debatable dates, no current affairs to keep up with. Pure, solid facts that haven't changed in decades. Vitamins cause the same diseases they did 50 years ago. The SI unit of force is still Newton. The pH of blood is still 7.4. Once you learn these facts, they're yours forever — no revision anxiety, no forgetting. In RRB NTPC, SSC, and Police exams, science typically contributes 10-15 questions. With the right approach, you can score 12-13 of those. Here's exactly how.

Biology: Guaranteed 3-4 Questions Every Exam

Vitamins and deficiency diseases — this table alone is worth 2-3 marks: Vitamin A (Retinol): Night blindness. Vitamin B1 (Thiamine): Beriberi. Vitamin B2 (Riboflavin): Ariboflavinosis (cracked lips). Vitamin B3 (Niacin): Pellagra. Vitamin B9 (Folic acid): Anemia in pregnancy. Vitamin B12 (Cobalamin): Pernicious anemia. Vitamin C (Ascorbic acid): Scurvy (bleeding gums). Vitamin D (Calciferol): Rickets (children), Osteomalacia (adults). Vitamin E (Tocopherol): Sterility. Vitamin K (Phylloquinone): Slow blood clotting. Trick: "Night Beriberi Pellagra Scurvy Rickets" = A, B1, B3, C, D — the five most asked combinations.

Other must-know Biology: Largest organ = Skin. Smallest bone = Stapes (ear). Largest bone = Femur (thigh). Blood groups = A, B, AB (universal recipient), O (universal donor). RBC made in = Bone marrow. Bile produced by = Liver (stored in gall bladder). Insulin produced by = Pancreas (beta cells). Hemoglobin contains = Iron. Plant cell vs Animal cell = plant has cell wall + chloroplast, animal doesn't. Photosynthesis equation = 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. These 10 facts appear in exams so often that not knowing them is basically throwing marks away.

Physics: Units, Instruments & Laws

SI Units — memorize this table, it appears in EVERY exam: Length = meter. Mass = kilogram. Time = second. Temperature = Kelvin. Electric current = Ampere. Luminous intensity = Candela. Amount of substance = Mole. Derived units that get asked: Force = Newton (kg·m/s²). Pressure = Pascal. Energy/Work = Joule. Power = Watt. Frequency = Hertz. Electric charge = Coulomb. Resistance = Ohm. Potential difference = Volt. Trick question alert: CGS unit of force is Dyne (not Newton). Weight is measured in Newton (not kg — kg is mass). Temperature conversions: °C to K = add 273. °C to °F = (9/5)C + 32.

Scientific instruments and their uses — another 1-2 guaranteed questions: Ammeter = electric current. Voltmeter = potential difference. Barometer = atmospheric pressure. Hygrometer = humidity. Lactometer = purity of milk. Seismograph = earthquake intensity. Thermometer = temperature. Stethoscope = heartbeat. Sphygmomanometer = blood pressure. Odometer = distance traveled by vehicle. Anemometer = wind speed. Fathometer = ocean depth. Rain Gauge = rainfall. Speedometer = speed. Altimeter = altitude. Learn these in pairs — instrument + what it measures. Use the app's flash cards for instruments — they're perfect for this kind of factual memorization.

Chemistry: Everyday Science That Gets Asked

pH values — these repeat every year: Lemon juice = 2 (acidic). Vinegar = 3. Tomato = 4. Coffee = 5. Milk = 6.5. Pure water = 7 (neutral). Blood = 7.4. Sea water = 8.5. Baking soda = 9. Milk of Magnesia = 10. Ammonia = 11.5. Bleach = 12.5. Remember: pH below 7 = acidic, above 7 = basic, exactly 7 = neutral. The fact that blood pH is 7.4 (slightly basic) is asked so frequently that it's almost criminal not to know it. Litmus paper: Red turns Blue in base, Blue turns Red in acid. Trick: "BR-BA" (Blue-Red = Base to Acid... backwards).

Chemical names of everyday substances — another exam favorite: Baking soda = Sodium Bicarbonate (NaHCO₃). Washing soda = Sodium Carbonate (Na₂CO₃). Bleaching powder = Calcium Hypochlorite (CaOCl₂). Plaster of Paris = Calcium Sulphate Hemihydrate (CaSO₄·½H₂O). Common salt = Sodium Chloride (NaCl). Caustic soda = Sodium Hydroxide (NaOH). Quick lime = Calcium Oxide (CaO). Slaked lime = Calcium Hydroxide (Ca(OH)₂). Vinegar = Acetic Acid (CH₃COOH). Laughing gas = Nitrous Oxide (N₂O). Dry ice = Solid CO₂. Rust = Iron Oxide (Fe₂O₃). Know the common name AND the chemical name — exams ask from both directions.

The NCERT Shortcut & Your Action Plan

Here's the truth that coaching centers won't tell you: NCERT Class 9 and 10 Science textbooks cover 90% of what's asked in government exams. You don't need expensive study material. Read NCERT 9-10 Science once, make notes of key facts, and then practice questions from the app. The app has all science chapters organized topic-wise — Biology, Physics, Chemistry — with the exact level of difficulty you'll face in the exam. Do one science chapter per day in the app. In 15 days, you'll cover all high-frequency science topics. Then revise using flash cards for 10 minutes every morning. Science isn't hard — it's the most honest section. Study the facts, know the facts, score the marks. No tricks, no luck, just pure preparation turning into pure marks.