General Science is an important part of the General Awareness or General Studies sections of many competitive examinations, including SSC CGL, SSC CHSL, SSC MTS, RRB NTPC, RRB Group D, railway recruitment examinations and various State Government exams.
A good understanding of Physics, Chemistry, Biology and Environmental Science can help candidates prepare for these examinations more effectively.
Here, you will find General Science MCQs with answers. The questions cover fundamental scientific concepts, human physiology, chemical reactions, motion, energy, diseases, plant biology, environmental science and everyday applications of science.
Whether you are preparing for SSC, Railway, Police, State PSC or other competitive examinations, use these practice questions to revise important concepts and identify topics that require further study.
Also, Read: MPESB Sub Engineer Thermodynamics Notes
General Science Syllabus for SSC, Railway and State Exams
Before practising the questions, review the major General Science topics commonly relevant to competitive examinations. The exact syllabus and depth of questions vary by examination.
| Subject | Important topics |
|---|---|
| Physics | Motion, force, work, energy, power, heat, sound, light, electricity, magnetism and scientific instruments |
| Chemistry | Elements, compounds, atoms, acids, bases, salts, metals, non-metals, chemical reactions and everyday chemistry |
| Biology | Cells, tissues, nutrition, respiration, reproduction, genetics, plants and classification of living organisms |
| Human Physiology | Digestive system, respiratory system, blood, heart, kidneys, hormones, vitamins and deficiency diseases |
| Environment | Ecosystems, food chains, pollution, biodiversity, conservation and climate change |
| Everyday Science | Household chemicals, common diseases, scientific discoveries, measurement and practical applications |
Section 1: Physics MCQs for SSC, Railway and State Exams
Q1. Which physical quantity is measured in newtons?
A. Work
B. Force
C. Power
D. Pressure
Correct Answer: B. Force
Explanation: The newton (N) is the SI unit of force. One newton is the force required to give a mass of one kilogram an acceleration of one metre per second squared. Work and energy are measured in joules, power in watts, and pressure in pascals.
Q2. Which law states that an object remains at rest or in uniform straight-line motion unless acted upon by a net external force?
A. Newton’s first law of motion
B. Newton’s second law of motion
C. Newton’s third law of motion
D. Law of universal gravitation
Correct Answer: A. Newton’s first law of motion
Explanation: Newton’s first law is also called the law of inertia. An object’s state of rest or uniform straight-line motion does not change unless a net external force acts on it.
Q3. What is the SI unit of power?
A. Joule
B. Newton
C. Watt
D. Pascal
Correct Answer: C. Watt
Explanation: Power is the rate at which work is done or energy is transferred. One watt equals one joule per second. The SI unit of energy and work is the joule.
Q4. Which type of mirror is commonly used as a rear-view mirror in vehicles?
A. Plane mirror
B. Concave mirror
C. Convex mirror
D. Parabolic mirror only
Correct Answer: C. Convex mirror
Explanation: A convex mirror provides an upright, virtual and diminished image and a wider field of view than a plane mirror. This allows drivers to see a larger area behind their vehicles.
Q5. Which phenomenon explains the splitting of white light into its constituent colours by a prism?
A. Reflection
B. Dispersion
C. Diffraction
D. Polarisation
Correct Answer: B. Dispersion
Explanation: Dispersion occurs because different wavelengths of light are refracted by different amounts in a material such as glass. White light separates into its constituent colours, commonly represented as violet, indigo, blue, green, yellow, orange and red.
Q6. Which medium allows sound to travel?
A. Perfect vacuum
B. Solid only
C. Gases only
D. Solids, liquids and gases
Correct Answer: D. Solids, liquids and gases
Explanation: Sound is a mechanical wave that requires a material medium. It can propagate through solids, liquids and gases but cannot travel through a perfect vacuum because there are no particles to transmit the disturbance.
Q7. Which instrument measures electric current?
A. Voltmeter
B. Ammeter
C. Barometer
D. Hydrometer
Correct Answer: B. Ammeter
Explanation: An ammeter measures electric current, expressed in amperes. It is generally connected in series with the circuit element whose current is being measured. A voltmeter measures potential difference.
Q8. What happens to the resistance of a metallic conductor when its temperature increases, assuming other relevant conditions remain unchanged?
A. It generally increases
B. It always becomes zero
C. It generally decreases
D. It remains exactly constant
Correct Answer: A. It generally increases
Explanation: In metals, higher temperatures generally cause stronger lattice vibrations, which impede the movement of conduction electrons. Consequently, electrical resistance usually increases with temperature over ordinary operating ranges.
Q9. Which form of energy is associated with an object because of its motion?
A. Chemical energy
B. Potential energy
C. Kinetic energy
D. Nuclear energy
Correct Answer: C. Kinetic energy
Explanation: Kinetic energy is the energy possessed by an object due to its motion. For an object of mass (m) moving at speed (v), its translational kinetic energy is (KE = \frac{1}{2}mv^2).
Q10. Why does a metal spoon feel colder than a wooden spoon when both have been kept in the same room for a long time?
A. Metal always has a lower temperature than wood
B. Wood contains no thermal energy
C. Metal conducts heat away from the hand more quickly
D. Wood produces heat when touched
Correct Answer: C. Metal conducts heat away from the hand more quickly
Explanation: When both objects are at the same room temperature, metal generally transfers heat away from the skin more rapidly because of its higher thermal conductivity. The difference in sensation does not mean the metal is necessarily at a lower temperature.
Section 2: Chemistry MCQs for Competitive Exams
Q11. What is the chemical symbol for sodium?
A. So
B. S
C. Na
D. N
Correct Answer: C. Na
Explanation: The symbol for sodium is Na, derived from the Latin name natrium. Sodium is an alkali metal and reacts readily with water, producing sodium hydroxide and hydrogen gas.
Q12. A solution with a pH of 3 is generally classified as:
A. Acidic
B. Neutral
C. Basic
D. Always saturated
Correct Answer: A. Acidic
Explanation: At approximately 25°C, a dilute aqueous solution with pH below 7 is acidic, pH 7 is neutral, and pH above 7 is basic. A pH of 3 indicates an acidic solution.
Q13. Which gas is released when an ordinary carbonate reacts with a suitable dilute acid?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Hydrogen
Correct Answer: B. Carbon dioxide
Explanation: Carbonates generally react with dilute acids to produce a salt, water and carbon dioxide. For example, calcium carbonate reacts with hydrochloric acid to form calcium chloride, water and carbon dioxide.
Q14. Which of the following is a noble gas?
A. Chlorine
B. Nitrogen
C. Oxygen
D. Argon
Correct Answer: D. Argon
Explanation: Argon belongs to Group 18 of the periodic table. Noble gases have relatively low chemical reactivity under ordinary conditions because of their stable valence-shell electron configurations.
Q15. What is the chemical formula of baking soda?
A. Na₂CO₃
B. NaHCO₃
C. CaCO₃
D. NaOH
Correct Answer: B. NaHCO₃
Explanation: Baking soda is sodium hydrogen carbonate, also called sodium bicarbonate. It is used in baking and can release carbon dioxide when it reacts with an acid or decomposes on heating.
Q16. Rusting of iron requires which conditions to proceed under ordinary circumstances?
A. Oxygen only, without moisture
B. Moisture only, without oxygen
C. Oxygen and moisture
D. Carbon dioxide alone
Correct Answer: C. Oxygen and moisture
Explanation: Ordinary rusting of iron generally requires both oxygen and water. Salts and other environmental conditions can accelerate corrosion. Rust is a mixture of hydrated iron oxides and related compounds rather than a single substance with one fixed composition.
Q17. Which method is commonly used to separate insoluble sand from water?
A. Filtration
B. Distillation
C. Sublimation
D. Chromatography
Correct Answer: A. Filtration
Explanation: Filtration separates an insoluble solid from a liquid by passing the mixture through a porous material. Sand is retained by the filter, while water passes through.
Q18. Which of the following is an example of a chemical change?
A. Melting of ice
B. Breaking a glass bottle
C. Dissolving sugar in water
D. Burning of paper
Correct Answer: D. Burning of paper
Explanation: Burning paper produces new substances, including gases and solid residues, through chemical reactions. Melting ice and breaking glass are physical changes, while dissolving sugar in water is generally a physical process.
Q19. Which particle determines the atomic number of an element?
A. Neutron
B. Proton
C. Electron
D. Proton plus neutron
Correct Answer: B. Proton
Explanation: The atomic number equals the number of protons in an atom’s nucleus. Atoms of the same element have the same atomic number, although they may have different numbers of neutrons and therefore be different isotopes.
Q20. Which gas is commonly used in fire extinguishers because it does not support ordinary combustion and can help displace oxygen around a fire?
A. Hydrogen
B. Oxygen
C. Carbon dioxide
D. Acetylene
Correct Answer: C. Carbon dioxide
Explanation: Carbon dioxide is used in certain fire extinguishers because it can displace oxygen near the fire and is non-flammable. Its suitability depends on the fire type and environment; it is not appropriate for every fire and can create an asphyxiation hazard in confined spaces.
Section 3: Biology MCQs for SSC, Railway and State Exams
Q21. Which cell organelle is primarily responsible for producing ATP through aerobic cellular respiration?
A. Ribosome
B. Mitochondrion
C. Golgi apparatus
D. Lysosome
Correct Answer: B. Mitochondrion
Explanation: Mitochondria are the main sites of most ATP production during aerobic cellular respiration in eukaryotic cells. ATP serves as a readily usable energy carrier for many cellular processes.
Q22. Which pigment absorbs light energy for photosynthesis in green plants?
A. Haemoglobin
B. Melanin
C. Chlorophyll
D. Keratin
Correct Answer: C. Chlorophyll
Explanation: Chlorophyll absorbs light energy used in photosynthesis. In plants, photosynthesis converts light energy into chemical energy and uses carbon dioxide and water to produce carbohydrates, releasing oxygen under oxygenic photosynthesis.
Q23. Which organ produces insulin in the human body?
A. Liver
B. Pancreas
C. Kidney
D. Thyroid gland
Correct Answer: B. Pancreas
Explanation: Insulin is produced by beta cells in the pancreatic islets. It helps regulate blood glucose by promoting glucose uptake in certain tissues and supporting glucose storage and metabolism.
Q24. Which component of blood is primarily responsible for transporting oxygen?
A. Platelets
B. Plasma proteins
C. Red blood cells
D. White blood cells
Correct Answer: C. Red blood cells
Explanation: Red blood cells contain haemoglobin, a protein that binds oxygen in the lungs and transports it to body tissues. Plasma carries many dissolved substances, white blood cells help defend against infection, and platelets are important in blood clotting.
Q25. Deficiency of vitamin C causes which disease?
A. Rickets
B. Scurvy
C. Beriberi
D. Night blindness
Correct Answer: B. Scurvy
Explanation: Vitamin C is necessary for normal collagen synthesis and connective-tissue maintenance. Severe deficiency can cause scurvy, which may involve bleeding gums, easy bruising and impaired wound healing.
Q26. Which part of the human brain is particularly important for balance and coordination of voluntary movement?
A. Cerebellum
B. Hypothalamus
C. Medulla oblongata
D. Cerebrum’s occipital lobe
Correct Answer: A. Cerebellum
Explanation: The cerebellum helps coordinate movement, maintain balance and regulate posture. It fine-tunes motor activity rather than independently initiating every voluntary movement.
Q27. What is the functional unit of the kidney?
A. Neuron
B. Alveolus
C. Nephron
D. Villus
Correct Answer: C. Nephron
Explanation: The nephron is the basic structural and functional unit of the kidney. It filters blood, reabsorbs useful substances, secretes selected substances into the tubule and contributes to urine formation.
Q28. Which type of blood vessel generally carries blood away from the heart?
A. Artery
B. Vein
C. Capillary only
D. Lymphatic vessel
Correct Answer: A. Artery
Explanation: Arteries carry blood away from the heart, while veins carry blood towards it. The oxygen content is not the defining feature: pulmonary arteries carry oxygen-poor blood, and pulmonary veins carry oxygen-rich blood.
Q29. Which process allows green plants to lose water vapour mainly through their leaves?
A. Translocation
B. Germination
C. Transpiration
D. Pollination
Correct Answer: C. Transpiration
Explanation: Transpiration is the loss of water vapour from a plant, mainly through stomata in the leaves. It contributes to water movement through the plant and helps regulate leaf temperature.
Q30. Which blood group is considered the universal red-cell donor type in routine transfusion terminology?
A. AB positive
B. O negative
C. A positive
D. B negative
Correct Answer: B. O negative
Explanation: O-negative red blood cells lack A, B and RhD antigens, making them the usual emergency universal red-cell donor type when compatibility cannot immediately be established. Crossmatching and clinical transfusion protocols remain important; this does not mean O-negative whole blood or plasma is universally compatible.
Section 4: Human Physiology, Diseases and Nutrition MCQs
Q31. Which enzyme in human saliva begins the digestion of starch?
A. Pepsin
B. Salivary amylase
C. Trypsin
D. Lipase only
Correct Answer: B. Salivary amylase
Explanation: Salivary amylase begins the breakdown of starch into smaller carbohydrates in the mouth. Further carbohydrate digestion occurs in the small intestine, where pancreatic amylase and other enzymes play important roles.
Q32. Which vitamin is essential for normal blood clotting and is required for the synthesis of several clotting factors?
A. Vitamin C
B. Vitamin D
C. Vitamin K
D. Vitamin B₁₂
Correct Answer: C. Vitamin K
Explanation: Vitamin K is required for the normal functioning of several blood-clotting proteins. A severe deficiency can impair clotting and increase bleeding risk.
Q33. Which microorganism causes tuberculosis?
A. Mycobacterium tuberculosis
B. Plasmodium falciparum
C. Influenza virus
D. Entamoeba histolytica
Correct Answer: A. Mycobacterium tuberculosis
Explanation: Tuberculosis is an infectious disease caused primarily by Mycobacterium tuberculosis, a bacterium. It most commonly affects the lungs but can also affect other organs.
Q34. Malaria is transmitted to humans primarily through the bite of an infected:
A. Female Anopheles mosquito
B. Male Anopheles mosquito
C. Housefly
D. Sandfly
Correct Answer: A. Female Anopheles mosquito
Explanation: Malaria is caused by Plasmodium parasites, which are transmitted to humans through the bites of infected female Anopheles mosquitoes. Houseflies do not transmit malaria in this way.
Q35. Which hormone plays a major role in regulating the body’s metabolic rate?
A. Insulin
B. Thyroxine
C. Adrenaline alone
D. Melatonin
Correct Answer: B. Thyroxine
Explanation: Thyroxine (T4), produced by the thyroid gland, is converted in tissues partly into the more active thyroid hormone T3. Thyroid hormones influence basal metabolic rate, growth and development.
Q36. Which part of the digestive system absorbs most nutrients from digested food?
A. Oesophagus
B. Stomach
C. Small intestine
D. Large intestine
Correct Answer: C. Small intestine
Explanation: Most nutrient absorption takes place in the small intestine. Its inner surface has folds, villi and microvilli that increase the surface area available for absorption.
Q37. Which deficiency is classically associated with rickets in children?
A. Vitamin C deficiency
B. Vitamin D deficiency
C. Vitamin K deficiency
D. Vitamin B₁ deficiency
Correct Answer: B. Vitamin D deficiency
Explanation: Vitamin D helps the body absorb calcium and phosphate, which are important for bone mineralisation. Deficiency during childhood can cause rickets, leading to weak or poorly mineralised bones. Other nutritional and medical factors can also contribute.
Q38. Which organ filters blood to remove many metabolic waste products and helps maintain water and electrolyte balance?
A. Kidney
B. Gallbladder
C. Spleen
D. Pancreas
Correct Answer: A. Kidney
Explanation: The kidneys filter blood plasma and regulate water, electrolytes and acid-base balance. They remove wastes such as urea through urine and also perform important hormonal functions.
Section 5: Environment and Everyday Science MCQs
Q39. Which gas is a major contributor to human-caused global warming?
A. Helium
B. Carbon dioxide
C. Neon
D. Argon
Correct Answer: B. Carbon dioxide
Explanation: Carbon dioxide is a major greenhouse gas emitted through fossil-fuel combustion, deforestation and several industrial processes. It absorbs and emits infrared radiation, contributing to the warming of Earth’s climate. Other greenhouse gases, including methane and nitrous oxide, also contribute.
Q40. Which layer of Earth’s atmosphere contains most of the ozone layer?
A. Troposphere
B. Stratosphere
C. Mesosphere
D. Exosphere
Correct Answer: B. Stratosphere
Explanation: Most atmospheric ozone is concentrated in the stratosphere. This ozone layer absorbs much of the Sun’s harmful ultraviolet radiation, helping protect life on Earth.
Q41. Which process converts atmospheric nitrogen into chemical forms that plants can ultimately use?
A. Nitrogen fixation
B. Transpiration
C. Photosynthesis alone
D. Evaporation
Correct Answer: A. Nitrogen fixation
Explanation: Nitrogen fixation converts atmospheric nitrogen gas into biologically usable nitrogen compounds. Certain bacteria perform this process, and industrial processes can also fix nitrogen. Plants generally absorb nitrogen through their roots in forms such as nitrate or ammonium.
Q42. Which of the following is a renewable source of energy?
A. Coal
B. Petroleum
C. Solar energy
D. Natural gas
Correct Answer: C. Solar energy
Explanation: Solar energy is replenished continuously by sunlight on human timescales. Coal, petroleum and natural gas are fossil fuels that form over geological timescales and are not replenished rapidly enough to be considered renewable.
Q43. What is the main purpose of biodegradable waste composting?
A. To convert organic waste into a more stable, useful material
B. To increase plastic production
C. To produce radioactive waste
D. To prevent all microbial activity permanently
Correct Answer: A. To convert organic waste into a more stable, useful material
Explanation: Composting uses microorganisms to break down suitable organic waste into a more stable material that can improve soil structure and supply nutrients. Effective composting depends on conditions such as moisture, oxygen, temperature and the waste mixture.
Q44. Which scientific instrument is used to measure atmospheric pressure?
A. Thermometer
B. Barometer
C. Hygrometer
D. Calorimeter
Correct Answer: B. Barometer
Explanation: A barometer measures atmospheric pressure. A thermometer measures temperature, a hygrometer measures humidity, and a calorimeter is used to measure heat exchanged in a process.
Q45. Which instrument is used to measure relative humidity?
A. Hygrometer
B. Ammeter
C. Seismograph
D. Speedometer
Correct Answer: A. Hygrometer
Explanation: A hygrometer measures humidity, including relative humidity. Relative humidity expresses the amount of water vapour in the air relative to the maximum amount the air could hold at the same temperature, usually as a percentage.
Q46. Which of the following is an example of an ecosystem?
A. A single mineral crystal
B. A community of organisms interacting with its physical environment
C. A single chemical element
D. A collection of unrelated laboratory instruments
Correct Answer: B. A community of organisms interacting with its physical environment
Explanation: An ecosystem consists of a biological community and its physical environment, including interactions involving energy flow and nutrient cycling. Examples include forests, ponds, grasslands and deserts.
Q47. Which human activity is a major source of sulphur dioxide emissions in many industrial regions?
A. Burning sulphur-containing fossil fuels
B. Collecting rainwater
C. Using solar panels
D. Planting native trees
Correct Answer: A. Burning sulphur-containing fossil fuels
Explanation: Burning coal or oil containing sulphur can release sulphur dioxide. This gas contributes to air pollution and can form sulphate particles and acids in the atmosphere. Emissions depend on fuel composition and pollution-control measures.
Q48. Which part of a plant primarily absorbs water and dissolved minerals from the soil?
A. Flower petals
B. Root system
C. Fruit skin
D. Pollen grains
Correct Answer: B. Root system
Explanation: Roots absorb water and mineral nutrients from the soil. Root hairs increase the surface area available for absorption, while xylem transports water and dissolved minerals to other parts of the plant.
Q49. What is the main reason soap is less effective at forming lather in hard water?
A. Hard water contains dissolved calcium and magnesium ions
B. Hard water contains no oxygen
C. Hard water has no dissolved minerals
D. Hard water always has a pH of exactly 7
Correct Answer: A. Hard water contains dissolved calcium and magnesium ions
Explanation: Calcium and magnesium ions react with many conventional soaps to form poorly soluble compounds called soap scum. This reduces lather formation and wastes soap. Synthetic detergents generally perform better in hard water.
Q50. Which energy transformation occurs in a simple electric bulb when it is switched on?
A. Electrical energy into light and thermal energy
B. Chemical energy into nuclear energy
C. Sound energy into gravitational energy
D. Nuclear energy into chemical energy
Correct Answer: A. Electrical energy into light and thermal energy
Explanation: An electric bulb converts electrical energy into light and heat. An incandescent bulb produces substantial heat, while LED bulbs generally convert a larger proportion of their electrical input into useful light.
How to Prepare General Science for SSC, Railway and State Exams
Solving MCQs is useful, but candidates should also understand why each answer is correct. A structured approach can help you retain information and recognise concepts when questions are presented differently.
1. Study one science subject at a time
Start with the basics of Physics, Chemistry and Biology. Study fundamental concepts before moving to fact-based questions. For example, understand force and motion before memorising their units and laws.
2. Practise topic-wise MCQs
Complete practice sets on individual topics such as electricity, acids and bases, human physiology, vitamins, diseases and environmental science. This makes it easier to identify weak areas.
3. Maintain a revision notebook
Record important formulas, scientific units, chemical symbols, vitamin deficiencies, diseases and their causative organisms. Keep explanations short and revise them regularly.
4. Solve previous year question papers
Use previous year papers from the relevant examination to understand its actual syllabus, question style and difficulty level. Prefer authentic papers and clearly labelled solutions, and distinguish official questions from newly created practice material.
5. Analyse mistakes
After each practice session, review every incorrect answer. Identify whether the mistake resulted from a forgotten fact, an unclear concept or misreading the question. Revisit the relevant topic before attempting another test.