General Science for RRB and SSC: Chapter-Wise Guide

General Science is the section where a little organised effort pays off the most. The syllabus is the science you studied in Classes 6 to 10, the questions are mostly one-liners, and a student who has read each chapter three times can score close to full marks while others lose time guessing. This guide walks through physics, chemistry, biology and everyday science chapter by chapter, with the facts, units and formulas that keep returning, memory aids, a 45-day plan and 30 practice questions with answers.

What the Exams Actually Ask

The weight of General Science differs from exam to exam, so always read the current notification before planning.

Exam	What is confirmed from public coverage
RRB Group D (Level 1)	CBT of 100 questions in 90 minutes, with 25 questions of General Science. Each wrong answer costs one-third of a mark.
RRB ALP (CBT-1)	75 questions in 60 minutes, with General Science as one of four subjects. One-third negative marking. CBT-1 is a screening stage.
RRB NTPC, Technician, SSC, police exams	Science appears inside General Awareness or General Knowledge. The number of science questions varies by exam and year, so check the latest notification and the latest paper analysis.

The level is school science, and the questions lean towards daily life: vitamins, diseases, acids and salts, electricity, light and the environment. Numerical questions are usually one formula and one step.

Across papers the question style falls into a few types:

• Match or odd one out: disease with cause, metal with ore, gland with hormone.
• One-step numerical: speed, force, work, resistance, power, lens power.

Physics, Chapter by Chapter

1. Motion and gravitation

Know the difference between distance (scalar) and displacement (vector), speed and velocity. Uniform circular motion is accelerated motion because the direction keeps changing. In a distance-time graph the slope is speed. In a velocity-time graph the slope is acceleration and the area under the line is distance.

Quantity	Formula	SI unit
Speed	distance / time	metre per second (m/s)
Acceleration	(v - u) / t	m/s squared
First equation	v = u + at
Second equation	s = ut + (1/2)at squared	metre
Third equation	v squared = u squared + 2as
Gravitation	F = G m1 m2 / r squared	newton

Facts to hold: G is about 6.67 x 10 to the power minus 11 N m squared per kg squared. The value of g near Earth's surface is about 9.8 m/s squared. Mass is measured in kilogram and stays constant everywhere, while weight is a force measured in newton and changes with g. The weight of a body on the Moon is about one-sixth of its weight on Earth. The escape velocity of Earth is about 11.2 km/s.

2. Force and laws of motion

Newton's first law is the law of inertia, the second gives F = ma and the third says every action has an equal and opposite reaction. Momentum is p = mv, in kg m/s, and it is conserved when no external force acts. A rocket and a gun recoil are the classic examples of the third law and of momentum conservation. The SI unit of force is the newton: 1 N = 1 kg m/s squared.

3. Pressure, density and floating

Pressure = force / area, unit pascal. Density = mass / volume. By Archimedes' principle, upthrust equals the weight of fluid displaced, so a body floats if its density is less than the liquid's. Standard atmospheric pressure is about 101325 Pa and the barometer measures it.

4. Work, energy and power

Quantity	Formula	Unit
Work	W = F x s x cos(theta)	joule (J)
Kinetic energy	(1/2) m v squared	joule
Potential energy	m g h	joule
Power	work / time	watt (W)
Horse power	1 hp = 746 W
Commercial unit	1 kWh = 3.6 x 10 to the power 6 J

Energy is never created or destroyed, only changed from one form to another. A battery converts chemical energy to electrical, a solar cell converts light to electrical, a generator converts mechanical to electrical, and the Sun's energy comes from nuclear fusion of hydrogen into helium. Nuclear power plants use fission, commonly of uranium-235. Remember that work is zero when the displacement is zero or when force is perpendicular to displacement.

5. Heat and temperature

The SI unit of temperature is the kelvin: K = degree Celsius + 273. F = (9/5) C + 32, and both scales read the same at minus 40. Normal body temperature is about 37 degrees Celsius (98.6 degrees Fahrenheit). Heat moves by conduction (solids), convection (liquids and gases) and radiation (needs no medium). Water has a high specific heat, which keeps coastal climates moderate. A pressure cooker works because higher pressure raises the boiling point.

6. Light

Light is transverse and travels in vacuum at about 3 x 10 to the power 8 m/s. Learn these items in a block:

• Mirror formula: 1/v + 1/u = 1/f, focal length f = R/2, magnification m = minus v/u.
• Lens formula: 1/v minus 1/u = 1/f. Power of a lens P = 1/f with f in metres; unit dioptre (D). Convex lens power is positive, concave is negative.
• Refractive index: n = sin i / sin r = speed of light in vacuum / speed in the medium. Water is about 1.33, ordinary glass about 1.5 and diamond about 2.42.
• Uses: concave mirrors in shaving mirrors, dentists' mirrors, torches and headlights; convex mirrors as vehicle rear-view mirrors because they give a wider field of view.
• Total internal reflection: optical fibres, the sparkle of diamond, mirage.
• Dispersion: a prism splits white light into VIBGYOR. Red bends least and has the longest wavelength; violet bends most. A rainbow is dispersion with refraction and internal reflection in water drops.
• Scattering: the sky is blue because shorter wavelengths scatter more; the Sun looks red at sunrise and sunset because the light travels a longer path. Red is used for danger signals because it scatters least.
• Eye: the cornea does most of the bending of light, the image forms on the retina, rods work in dim light and cones give colour vision. Normal near point is about 25 cm. Myopia (short sight) is corrected by a concave lens and hypermetropia (long sight) by a convex lens. Cataract is clouding of the eye lens. Stars twinkle due to atmospheric refraction; planets do not.

7. Sound

Sound is a longitudinal wave that needs a medium, so it cannot travel in vacuum. v = f x wavelength. It is fastest in solids and slowest in gases; in air it is roughly 330 to 345 m/s, and 340 m/s is the usual exam value. The audible range is 20 Hz to 20 kHz; below is infrasound and above is ultrasound. Pitch depends on frequency and loudness on amplitude (decibel). An echo needs a reflector at least about 17 m away. SONAR and medical scans use ultrasound.

8. Electricity

Item	Formula or fact	Unit
Current	I = Q / t	ampere (A)
Potential difference	work per unit charge	volt (V)
Ohm's law	V = I R	resistance in ohm
Series	R = R1 + R2 + R3
Parallel	1/R = 1/R1 + 1/R2 + 1/R3
Power	P = V I = I squared R = V squared / R	watt
Heating effect	H = I squared R t	joule

Charge is measured in coulomb, and the charge of one electron is about 1.6 x 10 to the power minus 19 C. An ammeter is connected in series and a voltmeter in parallel. Resistance depends on length, area of cross-section, material and temperature. Nichrome is used in heaters because of its high resistivity, and a fuse wire is a low-melting alloy placed in series with the live wire. Household appliances are connected in parallel. Domestic supply in India is 220 V at 50 Hz alternating current. The earth wire protects against shocks and the metal body of appliances is earthed. Overloading and short circuits are the two main causes of household circuit hazards.

9. Magnetism and electromagnetism

Outside a bar magnet field lines run from north to south and inside from south to north. Iron, cobalt and nickel are the common magnetic materials. Oersted showed that a current produces a magnetic field. Fleming's left-hand rule gives the direction of force on a current-carrying conductor, which is the principle of the electric motor. Electromagnetic induction, discovered by Faraday, is the principle of the generator, and Fleming's right-hand rule gives the direction of induced current. A motor converts electrical energy to mechanical, and a generator does the opposite. A transformer works on mutual induction and only with alternating current: step-up has more turns on the secondary. An electromagnet uses a soft iron core inside a solenoid.

Chemistry, Chapter by Chapter

1. Matter and its states

Matter exists as solid, liquid and gas, with plasma and Bose-Einstein condensate as the other two states usually listed. Ice melts at 273 K and water boils at 373 K at normal pressure. Sublimation is the direct change from solid to gas: camphor, naphthalene, ammonium chloride and dry ice (solid carbon dioxide). Evaporation happens at any temperature from the surface, while boiling happens at a fixed temperature throughout the liquid.

2. Atoms, molecules and the periodic table

• Laws: conservation of mass (Lavoisier) and constant proportions (Proust).
• Atomic models: Dalton (indivisible atom), Thomson (electron discovered, plum pudding model), Rutherford (nucleus, gold foil experiment with alpha particles), Bohr (fixed orbits). Chadwick discovered the neutron in 1932.
• Atomic number is the number of protons; mass number is protons plus neutrons. Isotopes have the same atomic number and different mass numbers; isobars have the same mass number; isotones have the same number of neutrons.
• Electron shells fill as 2, 8, 8, 2 for the first 20 elements. Valency is the combining capacity, decided by the outer electrons.
• Mole: one mole has 6.022 x 10 to the power 23 particles. The molar mass of water is 18 g and of carbon dioxide is 44 g.
• Periodic table: Mendeleev arranged elements by atomic mass; the modern table uses atomic number (Moseley). It has 18 groups and 7 periods. Noble gases are helium, neon, argon, krypton, xenon and radon. Helium is the second lightest gas and is used in balloons because it does not burn.

First twenty elements in order: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca. Symbols from Latin names: Na (natrium) sodium, K (kalium) potassium, Fe (ferrum) iron, Cu (cuprum) copper, Ag (argentum) silver, Au (aurum) gold, Pb (plumbum) lead, Sn (stannum) tin, Hg (hydrargyrum) mercury, W (wolfram) tungsten.

3. Acids, bases and salts

Item	Fact
pH scale	0 to 14. Below 7 acidic, 7 neutral, above 7 basic.
Blood	pH about 7.4, slightly basic
Stomach acid	Hydrochloric acid, pH about 1 to 2. Antacids such as milk of magnesia neutralise excess acid.
Tooth decay	Starts when mouth pH falls below about 5.5
Indicators	Litmus: acid turns blue to red, base turns red to blue. Phenolphthalein: colourless in acid, pink in base. Methyl orange: red in acid, yellow in base.
Natural acids	Vinegar: acetic. Lemon and orange: citric. Tamarind: tartaric. Curd: lactic. Apple: malic. Ant sting and nettle: methanoic (formic). Tea: tannic. Tomato: oxalic (with others).

Neutralisation: acid plus base gives salt plus water. Common salt NaCl comes from HCl and NaOH. The key household compounds are below.

Common name	Chemical name and formula	Use
Baking soda	Sodium hydrogencarbonate, NaHCO3	Antacid, baking, fire extinguishers
Washing soda	Sodium carbonate, Na2CO3 with 10 water molecules	Cleaning, softening hard water
Bleaching powder	Calcium oxychloride, CaOCl2	Disinfecting water, bleaching
Plaster of Paris	CaSO4 with half a molecule of water; made by heating gypsum (CaSO4 with 2 water molecules)	Casts for fractures, statues, ceilings
Quicklime	Calcium oxide, CaO	Cement, drying agent
Slaked lime	Calcium hydroxide, Ca(OH)2	Whitewash, treating acidic soil
Limestone and marble	Calcium carbonate, CaCO3	Cement, building
Baking powder	Baking soda plus a mild edible acid such as tartaric acid	Makes cakes rise

Hard water contains calcium and magnesium salts. Temporary hardness (bicarbonates) is removed by boiling; permanent hardness (chlorides and sulphates) needs washing soda or ion exchange. Soap does not lather well in hard water, which is a reason detergents are used.

4. Metals and non-metals

• Metals are lustrous, malleable, ductile and good conductors. Gold and silver are the most malleable and ductile; silver is the best conductor of heat and electricity, followed by copper.
• Mercury is the only metal liquid at room temperature; bromine is the only liquid non-metal. Diamond is a hard non-metal and graphite is a conducting non-metal; both are forms of carbon. Iodine is lustrous despite being a non-metal.
• Reactivity series (high to low): K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au. Sodium and potassium are stored in kerosene and white phosphorus in water.
• Aluminium oxide and zinc oxide are amphoteric.
• Ores: bauxite (aluminium), haematite (iron), cinnabar (mercury), galena (lead), zinc blende (zinc).
• Alloys: brass (copper and zinc), bronze (copper and tin), steel (iron and carbon), stainless steel (iron, chromium, nickel and carbon), solder (lead and tin), amalgam (any alloy with mercury).
• Rusting needs both oxygen and moisture. Prevention: painting, oiling, galvanisation (zinc coating).
• Aqua regia (three parts hydrochloric acid to one part nitric acid) dissolves gold and platinum.

5. Carbon and its compounds

Carbon is tetravalent and shows catenation, the ability to form long chains, which explains the huge number of carbon compounds. General formulas: alkanes CnH2n+2, alkenes CnH2n, alkynes CnH2n-2. Functional groups: alcohol (OH), aldehyde (CHO), ketone (C=O), carboxylic acid (COOH). Ethanol is the alcohol in drinks; ethanoic acid is vinegar's acid, and pure ethanoic acid freezes at about 17 degrees Celsius, hence the name glacial. Methane is the main part of CNG and biogas, and LPG is mainly butane with propane, with ethyl mercaptan added so leaks can be smelt. Soap is made by saponification, the reaction of fats or oils with a base such as NaOH. Esterification gives sweet-smelling esters. Hydrogen has the highest calorific value among common fuels.

Biology, Chapter by Chapter

1. Cell

Robert Hooke saw cells in cork in 1665. Schleiden and Schwann proposed the cell theory and Virchow added that new cells arise from existing cells. Robert Brown discovered the nucleus. Prokaryotes (bacteria) lack a true nucleus; eukaryotes have one.

Organelle	Job
Mitochondria	Release energy as ATP, the powerhouse
Ribosomes	Make proteins
Endoplasmic reticulum	Transport; rough ER carries ribosomes; smooth ER makes lipids
Golgi apparatus	Packaging and secretion
Lysosomes	Digest waste, called suicide bags
Plastids	Chloroplast holds chlorophyll for photosynthesis
Vacuole	Storage; large in plant cells
Cell wall	Made of cellulose; present in plants, not in animals

2. Tissues

Plant tissues are meristematic (growing) and permanent. Xylem carries water and minerals upward; phloem carries food. Animal tissues are epithelial, connective (blood, bone, cartilage, ligament, tendon), muscular and nervous. A tendon joins muscle to bone and a ligament joins bone to bone. Muscles are of three types: skeletal (striated, voluntary), smooth (involuntary) and cardiac (involuntary, found only in the heart). The neuron is the unit of the nervous system.

3. Human body systems

• Digestion: salivary amylase starts starch digestion in the mouth; pepsin acts in the stomach where hydrochloric acid creates acidity; bile from the liver emulsifies fats; the pancreas makes amylase, trypsin and lipase; absorption happens in the small intestine through villi. The liver is the largest gland. A normal adult has 32 teeth (8 incisors, 4 canines, 8 premolars, 12 molars).
• Blood and circulation: red cells carry haemoglobin (contains iron), white cells fight infection and platelets help clotting. Plasma is the liquid part. Blood groups of the ABO system were found by Landsteiner. Group O can donate to all in the ABO system and AB can receive from all. The heart has four chambers. Arteries carry blood away from the heart and veins bring it back; the pulmonary artery is the exception because it carries deoxygenated blood. Normal blood pressure is about 120/80 mm Hg. The SA node is the natural pacemaker. William Harvey described blood circulation.
• Respiration and excretion: gas exchange happens in alveoli of the lungs. The kidney, with nephrons as units, filters blood and forms urine. Urea is the main nitrogen waste in humans; dialysis replaces kidney function.
• Nervous system: the brain and spinal cord form the central nervous system. The cerebrum handles thought and memory, the cerebellum balance, and the medulla involuntary actions such as breathing. A reflex action is quick and involves the spinal cord.
• Endocrine system: the pituitary is called the master gland. The thyroid makes thyroxine and needs iodine. The pancreas makes insulin and its shortage causes diabetes. The adrenal gland makes adrenaline for emergencies.

4. Nutrition, vitamins and minerals

Carbohydrates and proteins give about 4 kcal per gram and fats about 9 kcal per gram. Protein deficiency causes kwashiorkor and marasmus.

Vitamin or mineral	Deficiency disease	Source
Vitamin A (retinol)	Night blindness, xerophthalmia	Carrot, papaya, milk, liver
Vitamin B1 (thiamine)	Beriberi	Whole grains, pulses
Vitamin B2 (riboflavin)	Cracks at mouth corners, sore tongue	Milk, eggs
Vitamin B3 (niacin)	Pellagra	Cereals, meat, groundnut
Vitamin B12 (cobalamin, contains cobalt)	Pernicious anaemia	Animal foods, such as milk and eggs
Vitamin C (ascorbic acid)	Scurvy	Amla, citrus fruits
Vitamin D	Rickets in children, osteomalacia in adults	Sunlight, fish liver oil, milk
Vitamin K	Delayed blood clotting	Green leafy vegetables
Iron	Anaemia	Spinach, jaggery, liver
Iodine	Goitre	Iodised salt, sea food
Calcium	Weak bones and teeth	Milk, ragi

Vitamins A, D, E and K are fat-soluble; B-complex and C are water-soluble. Vitamin D is made in the skin in sunlight.

5. Diseases

Cause	Examples
Bacteria	Cholera, typhoid, tuberculosis, tetanus, diphtheria, whooping cough, plague, leprosy, anthrax, pneumonia
Virus	AIDS, polio, measles, mumps, chickenpox, rabies, dengue, influenza, hepatitis A and B, chikungunya
Protozoa	Malaria (Plasmodium, spread by female Anopheles), amoebic dysentery, kala-azar (sand fly), sleeping sickness (tsetse fly)
Fungus	Ringworm, athlete's foot
Worms	Filaria or elephantiasis (Culex mosquito), ascariasis

Dengue and yellow fever spread through the Aedes mosquito. Antibiotics work against bacteria, not viruses. Edward Jenner developed the smallpox vaccine and smallpox was declared eradicated in 1980. Pasteur developed the rabies vaccine. Alexander Fleming discovered penicillin in 1928. The BCG vaccine is used against tuberculosis. Diabetes, cancer and heart disease are non-communicable.

6. Plants

Photosynthesis: carbon dioxide plus water, in sunlight and chlorophyll, gives glucose and oxygen. Stomata allow gas exchange and transpiration (loss of water vapour). Plant hormones: auxin (growth), gibberellin (stem elongation), cytokinin (cell division), abscisic acid (growth inhibitor, stress) and ethylene (ripening). Plants are classified as thallophyta, bryophyta, pteridophyta, gymnosperms and angiosperms. Angiosperms are monocots or dicots. Linnaeus gave binomial nomenclature and Whittaker the five-kingdom classification: Monera, Protista, Fungi, Plantae and Animalia.

7. Reproduction

Asexual methods: binary fission (amoeba), budding (yeast, hydra), fragmentation (Spirogyra), spores (Rhizopus), regeneration (planaria) and vegetative propagation (potato eyes, Bryophyllum leaves, rose cutting). In a flower the stamen is male (anther, filament) and the carpel or pistil is female (stigma, style, ovary). After pollination and fertilisation the ovary becomes the fruit and the ovule the seed. In humans fertilisation happens in the fallopian tube and the embryo implants in the uterus.

8. Ecology and environment

• Food chain: producers, then primary consumers, secondary consumers and decomposers. Only about 10 per cent of energy passes to the next trophic level (Lindeman).
• Greenhouse gases: carbon dioxide, methane, nitrous oxide, water vapour and CFCs. The ozone layer is in the stratosphere and blocks harmful ultraviolet rays. The Montreal Protocol (1987) targets ozone-depleting substances; the Paris Agreement (2015) deals with climate change.
• Acid rain has pH below 5.6 and comes from oxides of sulphur and nitrogen.
• Biomagnification: harmful chemicals such as DDT build up along the food chain. Eutrophication is excess nutrients in water bodies causing algal bloom.
• Indian laws: Wildlife (Protection) Act 1972, Water Act 1974, Air Act 1981 and Environment (Protection) Act 1986. Project Tiger began in 1973. World Environment Day is 5 June.
• Biogas (mostly methane) is made from cow dung and organic waste.

Everyday Science and Space Basics

Many questions are "why" questions with one-line answers. Keep a list like this:

• Sky is blue: scattering. Sunset is red: longer path through air.
• Mirage: total internal reflection. Rainbow: dispersion.
• Sunlight takes about 8 minutes to reach Earth. The Sun is a star; the Moon is a natural satellite of Earth. Jupiter is the largest planet, Mercury the smallest and closest to the Sun, and Venus the hottest. Mars is the red planet.

Memory Aids That Work

These are study tricks made for this guide. Make your own if they do not stick; the act of making one is itself revision.

• Rainbow order: VIBGYOR, violet to red; red bends least, so it has the longest wavelength.
• Fleming's left-hand rule: think FBI. Thumb is Force, forefinger is field (B), middle finger is current (I). Left hand is for motors; right hand is for generators.
• Vitamins: A for Appearance of the eye (night blindness), B1 for Beriberi, C for Citrus and scurvy, D for Dhoop (sunlight) and rickets, K for Knit (clotting).

The 45-Day Plan

This plan assumes about 90 minutes a day for science, on top of maths, reasoning and awareness. Each block ends with a 15-question quiz on that topic. Adjust the block length to your weak areas.

Days	Topic
1-2	Motion, gravitation, pressure
3-4	Force, work, energy, power
5-6	Heat and light
7	Sound
8-9	Electricity
10	Magnetism, electromagnetism
11-12	Physics revision and test
13-14	Matter, atoms, periodic table
15-16	Acids, bases, salts
17-18	Metals and non-metals
19-20	Carbon compounds, everyday chemistry
21-22	Chemistry revision and test
23	Cell and tissues
24-26	Digestion, blood, respiration, excretion
27	Nervous and endocrine systems
28-30	Nutrition, vitamins, diseases
31-33	Plants, classification, reproduction, heredity
34-35	Ecology and environment
36-37	Biology revision and test
38-40	Everyday science, space, inventions
41-45	Full revision, sectional tests, previous papers

How to Study Each Chapter

1. Read the NCERT chapter once for understanding. Do not highlight in the first pass.
2. Make a one-page sheet. Units, formulas, names, scientists and exceptions, in your own handwriting.
3. Solve 15 to 20 questions on that topic the same day. For physics, add 5 numerical sums.
4. Keep an error log. Write the question, your wrong answer, the right one and why. Check it every Sunday.
5. Revise on days 3, 7 and 21 after finishing a chapter. A ten-minute sheet recall is enough.
6. Draw diagrams for the heart, nephron, flower, eye and mirror ray diagrams. A drawing exposes gaps that reading does not.

Common Traps

• Weight versus mass: kg is mass, newton is weight.
• Convex or concave: the rear-view mirror is convex, a dentist's and shaving mirror concave. Myopia needs a concave lens.
• Sound versus light: sound needs a medium and is faster in solids; light does not need a medium.
• Arteries versus veins: do not say arteries always carry oxygenated blood. The pulmonary artery does not.
• Bacteria versus virus: TB, cholera, typhoid and tetanus are bacterial; polio, measles, dengue and AIDS are viral.
• Vitamin B12 and cobalt: B12 contains cobalt, not iron.

30 Practice Questions in Past-Paper Style

These are original practice questions written in the style of past papers; they are not actual exam questions. Try all 30 before reading the answers.

Physics

1. The SI unit of force is: (a) joule (b) newton (c) watt (d) pascal
2. A car starts from rest and accelerates at 2 m/s squared for 5 seconds. The distance covered is: (a) 10 m (b) 20 m (c) 25 m (d) 50 m
3. A force of 20 N acts on a body of mass 4 kg. The acceleration is: (a) 2 m/s squared (b) 5 m/s squared (c) 16 m/s squared (d) 80 m/s squared
4. The kinetic energy of a 2 kg body moving at 3 m/s is: (a) 3 J (b) 6 J (c) 9 J (d) 18 J
5. A machine does 600 J of work in 20 seconds. Its power is: (a) 12 W (b) 30 W (c) 120 W (d) 620 W
6. A convex lens has a focal length of 25 cm. Its power is: (a) +0.25 D (b) +2.5 D (c) +4 D (d) minus 4 D
7. Two resistors of 4 ohm each are joined in parallel. The equivalent resistance is: (a) 1 ohm (b) 2 ohm (c) 4 ohm (d) 8 ohm
8. A person hears an echo from a wall 85 m away. Taking the speed of sound as 340 m/s, the echo returns after: (a) 0.25 s (b) 0.5 s (c) 1 s (d) 2 s
9. Myopia is corrected using: (a) convex lens (b) concave lens (c) cylindrical lens (d) plane mirror
10. In household wiring a fuse is connected: (a) in parallel with the live wire (b) in series with the live wire (c) in series with the earth wire (d) across the neutral wire

Chemistry

11. The pH of normal human blood is closest to: (a) 2.0 (b) 5.5 (c) 7.4 (d) 10.5
12. The chemical formula of baking soda is: (a) Na2CO3 (b) NaHCO3 (c) NaOH (d) NaCl
13. Plaster of Paris is: (a) CaSO4 with 2 water molecules (b) CaSO4 with half a water molecule (c) CaCO3 (d) CaOCl2
14. Which is the most reactive among sodium, magnesium, zinc and copper? (a) sodium (b) magnesium (c) zinc (d) copper
15. The metal that is liquid at room temperature is: (a) sodium (b) mercury (c) lead (d) tin
16. Brass is an alloy of: (a) copper and tin (b) copper and zinc (c) iron and carbon (d) lead and tin
17. The general formula of alkenes is: (a) CnH2n+2 (b) CnH2n (c) CnH2n-2 (d) CnHn
18. The substance added to LPG so that a leak can be detected by smell is: (a) methane (b) ethyl mercaptan (c) ethanol (d) chlorine
19. Atoms of the same element with different mass numbers are called: (a) isobars (b) isotones (c) isotopes (d) allotropes
20. Coating iron with zinc to prevent rusting is called: (a) galvanisation (b) electrolysis (c) saponification (d) sublimation

Biology and Environment

21. The powerhouse of the cell is: (a) ribosome (b) lysosome (c) mitochondria (d) Golgi apparatus
22. Deficiency of vitamin A causes: (a) scurvy (b) rickets (c) night blindness (d) beriberi
23. Malaria is spread by: (a) female Anopheles mosquito (b) Aedes mosquito (c) Culex mosquito (d) housefly
24. The master gland of the human body is: (a) thyroid (b) pituitary (c) adrenal (d) pancreas
25. Insulin is produced by: (a) liver (b) pancreas (c) kidney (d) thyroid
26. Loss of water vapour from the leaves of plants through stomata is called: (a) respiration (b) transpiration (c) translocation (d) guttation
27. The number of chromosomes in a normal human body cell is: (a) 23 (b) 44 (c) 46 (d) 48
28. According to the ten per cent law, the energy passed from one trophic level to the next is about: (a) 1 per cent (b) 10 per cent (c) 50 per cent (d) 90 per cent
29. The ozone layer is found in the: (a) troposphere (b) stratosphere (c) mesosphere (d) exosphere
30. Scurvy is caused by lack of: (a) vitamin B1 (b) vitamin C (c) vitamin D (d) vitamin K

Answers

1-b, 2-c (25 m), 3-b (5 m/s squared), 4-c (9 J), 5-b (30 W), 6-c (+4 D), 7-b (2 ohm), 8-b (0.5 s, since 170 m / 340 m/s), 9-b, 10-b, 11-c, 12-b, 13-b, 14-a, 15-b, 16-b, 17-b, 18-b, 19-c, 20-a, 21-c, 22-c, 23-a, 24-b, 25-b, 26-b, 27-c, 28-b, 29-b, 30-b.

Score yourself with the exam's marking in mind: one mark for each right answer and one-third deducted for each wrong one. A raw score of 24 or more out of 30 means the topic list is under control. Below 20, go back to the error-log method and rework the section where you lost the most marks.

Frequently Asked Questions

How many science questions come in RRB Group D? The published pattern for Group D Level 1 has 25 questions of General Science in a 100-question paper. Check the latest notification in case the pattern is revised.

Is the syllabus only up to Class 10? The ALP and Group D syllabi describe the Class 10 standard of science. Other exams ask at a similar level, but check each notification for the exact list of topics.

Which of physics, chemistry and biology is the most scoring? Biology and everyday chemistry are usually easiest because they are fact based. Physics needs formulas but the sums are short. Do not skip any of them.

Do I need to memorise all formulas? Learn the formulas in the tables in this guide. They cover the numerical questions that commonly appear: motion, force, work, power, lens, sound and electricity.

Can I prepare from Hindi books? Yes, as long as you use NCERT as the reference for terms, units and facts. Where a guidebook and NCERT disagree, trust NCERT.

How much time should I give to science each day? About 60 to 90 minutes in a 45-day plan, with the first half learning and the second half questions and revision.

Is negative marking a big risk in science? Wrong answers lose one-third of a mark in the RRB papers described above. Attempt a question when you can remove at least two options; skip the ones you have never seen.

How do I remember the diseases and vitamins? Use tables, sort by cause, and test yourself with flashcards. Revise on days 3, 7 and 21 after first learning.

Practise Under Exam Conditions

Once you finish each block of the plan, take sectional tests on General Science, and in the last three weeks attempt full-length mock tests on Pareeksha to see how science fits into your overall time and accuracy. Log every wrong answer and fix it before the next test.