🧬 Biology — Most Repeated PYQ Questions
Biology · 18 Questions
Biology contributes the highest number of science questions in SSC exams. Focus on human body systems, vitamin deficiency diseases, blood groups, cell biology, and disease-causing organisms.
Biology · Q1
Which vitamin is produced by the human body when exposed to sunlight?
A) Vitamin A
B) Vitamin B12
C) Vitamin C
D) Vitamin D
✅ Answer: D) Vitamin D — Vitamin D (Calciferol) is synthesized in the skin on exposure to ultraviolet (UV) rays from sunlight. It is essential for calcium and phosphorus absorption. Deficiency of Vitamin D causes Rickets in children and Osteomalacia in adults.
Biology · Q2
Deficiency of which vitamin causes Night Blindness (Nyctalopia)?
A) Vitamin A
B) Vitamin B2
C) Vitamin C
D) Vitamin K
✅ Answer: A) Vitamin A — Vitamin A (Retinol) is essential for the production of rhodopsin, the light-sensitive pigment in the eye's rod cells. Deficiency leads to Night Blindness and also causes Xerophthalmia (dry eyes). Found in carrots, green leafy vegetables, and dairy.
Biology · Q3
Which blood group is known as the Universal Donor?
✅ Answer: C) O− — O negative (O−) blood group is called the Universal Donor because it lacks both A and B antigens, as well as the Rh factor, so it can be given to any blood group recipient. AB+ is the Universal Recipient — it can receive from all groups.
Biology · Q4
Which part of the human body produces insulin?
A) Liver
B) Kidney
C) Pancreas
D) Thyroid gland
✅ Answer: C) Pancreas — Insulin is produced by the Beta cells of the Islets of Langerhans in the pancreas. Insulin regulates blood glucose levels. Deficiency or ineffective use of insulin causes Diabetes Mellitus. Glucagon (raises blood sugar) is produced by the Alpha cells of the same structure.
Biology · Q5
Which part of the human eye controls the amount of light entering it?
A) Cornea
B) Retina
C) Iris
D) Lens
✅ Answer: C) Iris — The iris is the coloured part of the eye that controls the diameter of the pupil. In bright light, the iris makes the pupil smaller to reduce light entry. In dim light, it widens the pupil to allow more light in. The retina receives the image, and the lens focuses it.
Biology · Q6
The deficiency of which vitamin leads to Scurvy?
A) Vitamin A
B) Vitamin B12
C) Vitamin C
D) Vitamin D
✅ Answer: C) Vitamin C — Vitamin C (Ascorbic acid) deficiency causes Scurvy, characterised by bleeding gums, skin spots, and joint pain. It was historically common among sailors who had no access to fresh fruits. Good sources: citrus fruits, amla, guava.
Biology · Q7
Which is the largest organ of the human body?
A) Liver
B) Brain
C) Skin
D) Intestine
✅ Answer: C) Skin — The skin is the largest organ of the human body by surface area (about 1.5–2 sq. metres) and weight. The liver is the largest internal (glandular) organ. The small intestine is the longest internal organ (~6–7 metres).
Biology · Q8
Which disease is caused by deficiency of Vitamin B12?
A) Beri-beri
B) Pernicious Anaemia
C) Pellagra
D) Rickets
✅ Answer: B) Pernicious Anaemia — Vitamin B12 (Cobalamin) deficiency causes Pernicious Anaemia, where the body cannot produce enough healthy red blood cells. Beri-beri is caused by Vitamin B1 (Thiamine) deficiency. Pellagra by Vitamin B3 (Niacin) deficiency.
Biology · Q9
Which organelle is called the "Powerhouse of the Cell"?
A) Nucleus
B) Ribosome
C) Mitochondria
D) Golgi body
✅ Answer: C) Mitochondria — Mitochondria produce ATP (Adenosine Triphosphate), the energy currency of the cell, through cellular respiration. Hence they are called the powerhouse of the cell. The nucleus is the control centre. Ribosomes are the site of protein synthesis.
Biology · Q10
Which disease is caused by the bite of an Anopheles mosquito?
A) Dengue
B) Malaria
C) Chikungunya
D) Filariasis
✅ Answer: B) Malaria — Malaria is caused by the Plasmodium parasite, transmitted by the female Anopheles mosquito. Dengue and Chikungunya are spread by Aedes mosquitoes. Filariasis (elephantiasis) is caused by a parasitic worm spread by Culex mosquitoes.
Biology · Q11
Which vitamin is essential for blood clotting?
A) Vitamin C
B) Vitamin D
C) Vitamin E
D) Vitamin K
✅ Answer: D) Vitamin K — Vitamin K is essential for the synthesis of prothrombin and other clotting factors. Without it, even small cuts can lead to excessive bleeding. Found in green leafy vegetables, liver, and fermented foods.
Biology · Q12
Where does the digestion of protein begin in the human body?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
✅ Answer: B) Stomach — Protein digestion begins in the stomach with the enzyme Pepsin, activated by hydrochloric acid (HCl). Carbohydrate digestion begins in the mouth with Salivary Amylase. Fat digestion begins in the small intestine with bile and Lipase.
Biology · Q13
The human heart has how many chambers?
✅ Answer: C) 4 — The human heart has four chambers: two upper chambers (Right Atrium and Left Atrium) and two lower chambers (Right Ventricle and Left Ventricle). The right side pumps deoxygenated blood to the lungs; the left side pumps oxygenated blood to the body.
Biology · Q14
Which gas is exchanged in the alveoli of the lungs?
A) Nitrogen and Carbon dioxide
B) Oxygen and Carbon dioxide
C) Oxygen and Nitrogen
D) Carbon monoxide and Oxygen
✅ Answer: B) Oxygen and Carbon dioxide — In the alveoli (tiny air sacs in lungs), Oxygen diffuses into the blood while Carbon dioxide diffuses out of the blood into the alveoli to be exhaled. This gas exchange happens via passive diffusion across the thin alveolar walls.
Biology · Q15
What is the normal range of human body temperature in Celsius?
A) 34–35°C
B) 36–37°C
C) 38–39°C
D) 40–41°C
✅ Answer: B) 36–37°C — Normal human body temperature is approximately 37°C (98.6°F). A temperature above 38°C is medically considered a fever (Pyrexia). Body temperature is regulated by the hypothalamus in the brain.
Biology · Q16
Which is the longest bone in the human body?
A) Humerus
B) Tibia
C) Femur
D) Spine
✅ Answer: C) Femur — The femur (thigh bone) is the longest and strongest bone in the human body. The smallest bone is the Stapes in the middle ear. An adult human has 206 bones in total.
Biology · Q17
Beri-beri disease is caused by the deficiency of which vitamin?
A) Vitamin B1
B) Vitamin B2
C) Vitamin B6
D) Vitamin B12
✅ Answer: A) Vitamin B1 (Thiamine) — Beri-beri is caused by Vitamin B1 (Thiamine) deficiency. It affects the nervous system (dry beri-beri) and the cardiovascular system (wet beri-beri). Common in populations relying heavily on polished white rice.
Biology · Q18
Which part of the brain controls balance and coordination of movement?
A) Cerebrum
B) Cerebellum
C) Medulla oblongata
D) Hypothalamus
✅ Answer: B) Cerebellum — The cerebellum (located at the back of the brain) controls balance, posture, and coordination of voluntary movements. The cerebrum controls higher functions like thinking and memory. Medulla oblongata controls involuntary functions like breathing and heartbeat.
⚡ Physics — Most Repeated PYQ Questions
Physics · 16 Questions
Physics questions in SSC focus on laws of motion, units of measurement, light, sound, and electricity. These are largely formulaic and once understood, the same concepts appear in slightly different question formats every year.
Physics · Q1
What is the SI unit of electric current?
A) Volt
B) Watt
C) Ampere
D) Ohm
✅ Answer: C) Ampere — The SI unit of electric current is Ampere (A), named after André-Marie Ampère. Volt is the unit of electric potential difference. Watt is the unit of power. Ohm is the unit of electrical resistance.
Physics · Q2
Newton's First Law of Motion is also known as the Law of?
A) Acceleration
B) Inertia
C) Action-Reaction
D) Gravitation
✅ Answer: B) Inertia — Newton's First Law states that a body remains at rest or in uniform motion unless acted upon by an external force. This property of resisting change in motion is called Inertia. Example: passengers jerk forward when a bus brakes suddenly.
Physics · Q3
What is the approximate speed of light in vacuum?
A) 3 × 10⁶ m/s
B) 3 × 10⁸ m/s
C) 3 × 10¹⁰ m/s
D) 3 × 10⁴ m/s
✅ Answer: B) 3 × 10⁸ m/s — The speed of light in vacuum is approximately 3 × 10⁸ m/s (300,000 km/s). Sound, by contrast, travels at about 343 m/s in air. Light travels approximately 874,000 times faster than sound.
Physics · Q4
Which instrument is used to measure atmospheric pressure?
A) Thermometer
B) Hygrometer
C) Barometer
D) Anemometer
✅ Answer: C) Barometer — A Barometer measures atmospheric (air) pressure. Thermometer measures temperature. Hygrometer measures humidity. Anemometer measures wind speed. A Seismograph measures earthquake intensity.
Physics · Q5
The phenomenon of splitting of white light into its constituent colours is called?
A) Reflection
B) Refraction
C) Dispersion
D) Diffraction
✅ Answer: C) Dispersion — Dispersion is the splitting of white light into its seven constituent colours (VIBGYOR) when it passes through a prism. This happens because different colours have different wavelengths and travel at different speeds in a medium. A rainbow is a natural example of dispersion.
Physics · Q6
What is the SI unit of force?
A) Joule
B) Newton
C) Pascal
D) Watt
✅ Answer: B) Newton (N) — The SI unit of force is Newton, named after Sir Isaac Newton. 1 Newton = the force required to accelerate 1 kg mass at 1 m/s². Joule is the unit of energy/work. Pascal is the unit of pressure. Watt is the unit of power.
Physics · Q7
Which mirror is used as a rear-view mirror in vehicles?
A) Plane mirror
B) Concave mirror
C) Convex mirror
D) Parabolic mirror
✅ Answer: C) Convex mirror — Convex mirrors are used as rear-view mirrors because they provide a wider field of view, showing a larger area behind the vehicle, though the images appear smaller and further away. Concave mirrors are used in headlights, shaving mirrors, and solar concentrators.
Physics · Q8
Sound cannot travel through which medium?
A) Water
B) Steel
C) Air
D) Vacuum
✅ Answer: D) Vacuum — Sound is a mechanical wave that requires a medium to travel. It cannot travel through vacuum (empty space). Sound travels fastest in solids (like steel), slower in liquids (like water), and slowest in gases (like air). This is why there is silence in outer space.
Physics · Q9
Which law states: "For every action, there is an equal and opposite reaction"?
A) Newton's First Law
B) Newton's Second Law
C) Newton's Third Law
D) Law of Conservation
✅ Answer: C) Newton's Third Law — Newton's Third Law of Motion: every action has an equal and opposite reaction. Example: a rocket moves forward by expelling gases backward. Second Law: F = ma (force equals mass times acceleration).
Physics · Q10
The unit of electrical resistance is?
A) Ampere
B) Volt
C) Ohm
D) Farad
✅ Answer: C) Ohm (Ω) — Electrical resistance is measured in Ohm (Ω), named after Georg Simon Ohm. Ohm's Law: V = IR (Voltage = Current × Resistance). Farad is the unit of capacitance. Henry is the unit of inductance.
Physics · Q11
What is the SI unit of pressure?
A) Newton
B) Pascal
C) Bar
D) Joule
✅ Answer: B) Pascal (Pa) — Pascal is the SI unit of pressure, named after Blaise Pascal. 1 Pascal = 1 Newton per square metre (N/m²). Atmospheric pressure at sea level is approximately 101,325 Pa (or 1 atm).
Physics · Q12
Which colour of light has the highest frequency in the visible spectrum?
A) Red
B) Yellow
C) Green
D) Violet
✅ Answer: D) Violet — In the visible spectrum (VIBGYOR), Violet has the highest frequency and shortest wavelength. Red has the lowest frequency and longest wavelength. This is why red is least bent and violet is most bent during dispersion through a prism.
Physics · Q13
Which device converts mechanical energy into electrical energy?
A) Motor
B) Transformer
C) Generator
D) Battery
✅ Answer: C) Generator — A Generator (or Dynamo) converts mechanical energy into electrical energy using the principle of electromagnetic induction. A Motor does the reverse — converts electrical energy to mechanical energy. A Transformer changes voltage levels in AC circuits.
Physics · Q14
What is the unit of measurement of frequency?
A) Decibel
B) Hertz
C) Watt
D) Candela
✅ Answer: B) Hertz (Hz) — Frequency is measured in Hertz (Hz), named after Heinrich Hertz. 1 Hz = 1 cycle per second. Decibel (dB) measures sound intensity. Candela measures luminous intensity. Human hearing range is 20 Hz to 20,000 Hz.
Physics · Q15
Which type of lens is used to correct Myopia (short-sightedness)?
A) Convex lens
B) Concave lens
C) Bifocal lens
D) Cylindrical lens
✅ Answer: B) Concave lens — Myopia (near-sightedness) is corrected using a Concave (diverging) lens. Hypermetropia (far-sightedness) is corrected using a Convex (converging) lens. Presbyopia (age-related) uses Bifocal lenses. Astigmatism uses Cylindrical lenses.
Physics · Q16
What is the SI unit of work and energy?
A) Watt
B) Newton
C) Joule
D) Pascal
✅ Answer: C) Joule (J) — The SI unit of work and energy is Joule, named after James Prescott Joule. 1 Joule = force of 1 Newton applied over a distance of 1 metre. Power is measured in Watts (1 Watt = 1 Joule per second).
🧪 Chemistry — Most Repeated PYQ Questions
Chemistry · 16 Questions
Chemistry questions focus on acids and bases, common chemical compounds, metals and their properties, and everyday chemistry. These are factual and highly predictable.
Chemistry · Q1
Which gas is used in fire extinguishers?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Hydrogen
✅ Answer: C) Carbon Dioxide (CO₂) — CO₂ is used in fire extinguishers because it is heavier than air, non-flammable, and cuts off the oxygen supply to the fire. It does not leave any residue. For electrical fires, CO₂ is especially preferred as it is non-conductive.
Chemistry · Q2
What is the chemical formula of common salt (table salt)?
A) NaOH
B) NaCl
C) CaCl₂
D) KCl
✅ Answer: B) NaCl — Common salt (Sodium Chloride) has the formula NaCl. NaOH is Sodium Hydroxide (caustic soda). CaCl₂ is Calcium Chloride (used as a desiccant). KCl is Potassium Chloride. Baking soda is NaHCO₃ (Sodium Bicarbonate).
Chemistry · Q3
The pH value of pure water is?
✅ Answer: C) 7 — Pure water has a neutral pH of 7. pH below 7 indicates acidic solution; above 7 is basic/alkaline. Lemon juice ≈ pH 2 (acidic). Blood ≈ pH 7.4 (slightly alkaline). Caustic soda ≈ pH 14 (strongly alkaline).
Chemistry · Q4
Which acid is present in vinegar?
A) Citric acid
B) Acetic acid
C) Lactic acid
D) Tartaric acid
✅ Answer: B) Acetic acid (CH₃COOH) — Vinegar contains 5–8% Acetic acid. Citric acid is found in lemons and citrus fruits. Lactic acid is present in sour milk and curd. Tartaric acid is found in grapes and tamarind. Formic acid is found in ant stings.
Chemistry · Q5
Which gas is responsible for the greenhouse effect?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Argon
✅ Answer: C) Carbon Dioxide (CO₂) — CO₂ is the primary greenhouse gas responsible for global warming. Other greenhouse gases include Methane (CH₄), Nitrous Oxide (N₂O), and Water vapour. The greenhouse effect refers to these gases trapping the sun's heat in Earth's atmosphere.
Chemistry · Q6
What is the chemical name of baking soda?
A) Sodium carbonate
B) Sodium chloride
C) Sodium bicarbonate
D) Calcium carbonate
✅ Answer: C) Sodium Bicarbonate (NaHCO₃) — Baking soda is Sodium Bicarbonate (NaHCO₃). Washing soda is Sodium Carbonate (Na₂CO₃). Baking powder is a mixture of baking soda + an acid (like cream of tartar). Common salt is Sodium Chloride (NaCl).
Chemistry · Q7
Bronze is an alloy of which two metals?
A) Copper and Zinc
B) Copper and Tin
C) Iron and Carbon
D) Aluminium and Copper
✅ Answer: B) Copper and Tin — Bronze = Copper + Tin. Brass = Copper + Zinc. Steel = Iron + Carbon. Stainless Steel = Iron + Carbon + Chromium + Nickel. Duralumin = Aluminium + Copper + Manganese + Magnesium (used in aircraft).
Chemistry · Q8
Which gas is produced when baking soda reacts with an acid?
A) Oxygen
B) Hydrogen
C) Carbon Dioxide
D) Nitrogen
✅ Answer: C) Carbon Dioxide (CO₂) — When baking soda (NaHCO₃) reacts with an acid (like vinegar or citric acid), it produces CO₂ gas. This CO₂ creates bubbles that make cakes and bread rise and become fluffy. This is the principle of chemical leavening in baking.
Chemistry · Q9
Which is the hardest natural substance on Earth?
A) Gold
B) Iron
C) Diamond
D) Quartz
✅ Answer: C) Diamond — Diamond is the hardest known natural substance, rating 10 on the Mohs hardness scale. It is a form (allotrope) of Carbon. Graphite is another allotrope of Carbon — it is soft and is used in pencils. Diamond's hardness makes it useful in cutting and drilling tools.
Chemistry · Q10
What is the chemical formula of ozone?
✅ Answer: C) O₃ — Ozone is a triatomic molecule of oxygen with the formula O₃. The ozone layer in the stratosphere absorbs harmful UV radiation from the sun. CFCs (Chlorofluorocarbons) are primarily responsible for ozone layer depletion.
Chemistry · Q11
Which acid is present in lemon?
A) Acetic acid
B) Lactic acid
C) Citric acid
D) Tartaric acid
✅ Answer: C) Citric acid — Lemons and other citrus fruits contain Citric acid, which gives them their sour taste. Lactic acid is found in sour curd and fermented foods. Oxalic acid is found in tomatoes and spinach. Formic acid (methanoic acid) is found in ant stings.
Chemistry · Q12
Rusting of iron is an example of which type of chemical reaction?
A) Reduction
B) Oxidation
C) Neutralisation
D) Decomposition
✅ Answer: B) Oxidation — Rusting is the oxidation of iron in the presence of water and oxygen, forming iron oxide (Fe₂O₃·xH₂O). It is an electrochemical process. Rusting can be prevented by galvanisation (coating with zinc), painting, or oiling.
Chemistry · Q13
Which gas is called "Laughing Gas"?
A) Nitric oxide (NO)
B) Nitrogen dioxide (NO₂)
C) Nitrous oxide (N₂O)
D) Ammonia (NH₃)
✅ Answer: C) Nitrous oxide (N₂O) — Nitrous Oxide (N₂O) is called Laughing Gas because inhaling small amounts causes euphoria and involuntary laughter. It is also used as an anaesthetic in dentistry. It is a greenhouse gas and contributes to ozone depletion.
Chemistry · Q14
The process of conversion of sugar into alcohol by yeast is called?
A) Oxidation
B) Fermentation
C) Pasteurisation
D) Hydrogenation
✅ Answer: B) Fermentation — Fermentation is the anaerobic (without oxygen) process by which yeast converts sugar (glucose) into ethanol (alcohol) and CO₂. Pasteurisation (by Louis Pasteur) is the process of heating food/drink to kill pathogens. Hydrogenation converts liquid oils to solid fats.
Chemistry · Q15
Which metal is liquid at room temperature?
A) Sodium
B) Gallium
C) Mercury
D) Caesium
✅ Answer: C) Mercury (Hg) — Mercury is the only metal that is liquid at room temperature (melting point -38.8°C). Bromine is a non-metal that is also liquid at room temperature. Mercury is used in thermometers, barometers, and dental fillings.
Chemistry · Q16
Which gas is used in electric bulbs to prevent the filament from burning?
A) Oxygen
B) Carbon dioxide
C) Nitrogen or Argon
D) Hydrogen
✅ Answer: C) Nitrogen or Argon — Electric bulbs are filled with inert gases (Nitrogen or Argon) to prevent the tungsten filament from oxidising and burning out. These gases do not react with the filament. Neon is used in neon signs (glows orange-red). Krypton is used in energy-saving bulbs.
📋 Science Preparation Strategy for SSC & Railway Exams
Step 1 — Start with Biology (Highest ROI)
Biology gives you the most questions with the least effort. Make a one-page chart of vitamin deficiency diseases (from the table above) and revise it daily for 7 days. Then cover human body systems: digestive, respiratory, circulatory, nervous. After that, study disease-causing organisms (bacteria, viruses, parasites).
Step 2 — Physics: Units First, Concepts Second
Memorise the SI units table completely — this alone guarantees 1–2 questions per paper. Then study Newton's laws with real-life examples, then light (mirrors and lenses), then sound. Don't go deep into derivations — focus on conceptual understanding and facts.
Step 3 — Chemistry: Focus on Everyday Chemistry
For SSC CGL, Chemistry is less theory-heavy and more about everyday facts. Know your alloys (Bronze, Brass, Steel), natural acids (the table above), common chemical formulas (NaCl, NaOH, H₂SO₄, CO₂), and the pH scale. The greenhouse effect and ozone depletion questions also appear frequently.
Step 4 — Daily Practice on GK Capsule
After building your conceptual base from NCERT Class 8–10 Science, use GK Capsule's daily practice to drill PYQs. The spaced repetition effect of answering 5–10 questions every morning means you'll retain these facts much longer than cramming sessions.
📚 Best Books for Science GK: NCERT Science Class 8, 9, and 10 are the foundation. For quick revision, Lucent's General Science covers all SSC-level topics. After covering concepts, shift exclusively to PYQ practice — the questions on this page are directly from real SSC and Railway papers.