Physics questions in KEA papers test units, simple laws and how science works in daily life: mirrors, lenses, sound, electricity and magnets.
- The SI system has 7 base units: metre (length), kilogram (mass), second (time), ampere (current), kelvin (temperature), mole (amount) and candela (light intensity).
- Derived units: newton (force), joule (work/energy), watt (power), pascal (pressure), hertz (frequency), volt (potential), ohm (resistance).
- Newton's first law (inertia): a body stays at rest or in uniform motion unless a force acts on it. Second law: F = m x a. Third law: every action has an equal and opposite reaction.
- A rocket moving up and recoil of a gun are examples of the third law.
- Acceleration due to gravity (g) on Earth is about 9.8 m/s². Weight changes from place to place; mass does not.
- Light travels at about 3 x 10^8 m/s in vacuum. Sound needs a medium and cannot travel in vacuum.
- Total internal reflection makes diamonds sparkle and is used in optical fibres. Dispersion of sunlight by water drops forms a rainbow.
- The sky looks blue because of scattering of light. C. V. Raman won the Nobel Prize in 1930 for the Raman effect; National Science Day is 28 February.
- Concave mirrors are used in torches and for shaving; convex mirrors are used as rear-view mirrors in vehicles.
- Short-sight (myopia) is corrected with a concave lens; long-sight (hypermetropia) with a convex lens.
- Humans hear 20 Hz to 20,000 Hz. Sound above 20,000 Hz is ultrasound, used by bats and in SONAR and medical scans.
- Ohm's law: V = I x R. Current is measured in amperes with an ammeter; voltage with a voltmeter.
- Household supply in India is about 230 V AC at 50 Hz. Electricity bills count 'units': 1 unit = 1 kilowatt-hour (kWh).
- A fuse melts and breaks the circuit when too much current flows. Earthing protects users from shocks.
- An electric motor changes electrical energy into mechanical energy; a generator (dynamo) does the opposite.
- Michael Faraday discovered electromagnetic induction. A transformer works only on AC and changes voltage.
- Force
- newton
- Energy
- joule
- Power
- watt
- Pressure
- pascal
- 1 unit of electricity
- 1 kWh
- Speed of light
- 3 x 10^8 m/s
- Audible range
- 20 Hz - 20 kHz
- Rear-view mirror
- Convex
- Myopia lens
- Concave
💡 Make a two-column list 'quantity - unit' and revise it daily. Unit questions are easy marks if you remember them exactly.
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Chemistry questions ask about matter, atoms, acids and bases, everyday chemicals and metals. Many can be answered by linking a chemical to its use.
- Matter exists as solid, liquid and gas. Changing directly from solid to gas is sublimation (camphor, naphthalene, dry ice).
- An atom has protons and neutrons in the nucleus and electrons around it. J. J. Thomson found the electron; James Chadwick found the neutron (1932).
- Hydrogen is the lightest element. Mercury is a metal that is liquid at room temperature; bromine is a liquid non-metal.
- Air is about 78% nitrogen and 21% oxygen. Oxygen is the most abundant element in the Earth's crust; aluminium is the most abundant metal there.
- Diamond and graphite are both forms of carbon. Diamond is the hardest natural substance; graphite conducts electricity.
- The pH scale runs from 0 to 14. Below 7 is acidic, 7 is neutral (pure water), above 7 is basic. Human blood is slightly basic (about 7.4).
- Natural acids: citric acid (lemon), lactic acid (curd), acetic acid (vinegar), tartaric acid (tamarind), formic acid (ant sting).
- Our stomach makes hydrochloric acid. Antacids such as milk of magnesia (magnesium hydroxide) neutralise extra acid.
- Acid + base gives salt + water (neutralisation). Litmus turns red in acid and blue in base.
- Common salt: sodium chloride. Baking soda: sodium bicarbonate. Washing soda: sodium carbonate. Bleaching powder: calcium oxychloride.
- Plaster of Paris is made by heating gypsum; used for fractures and statues. Dry ice is solid carbon dioxide. Laughing gas is nitrous oxide.
- LPG is mainly butane and propane; CNG is mainly methane. Ozone (O3) in the upper atmosphere blocks ultraviolet rays.
- Silver is the best conductor of electricity; copper is widely used in wires. Rusting of iron needs both water and oxygen.
- Galvanisation is coating iron with zinc to stop rust. Alloys: brass (copper + zinc), bronze (copper + tin), steel (iron + carbon); stainless steel adds chromium and nickel.
- Neutral pH
- 7
- Baking soda
- Sodium bicarbonate
- Washing soda
- Sodium carbonate
- Vinegar
- Acetic acid
- Stomach acid
- Hydrochloric acid
- Brass
- Copper + zinc
- Galvanising metal
- Zinc
- Liquid metal
- Mercury
- Main gas in air
- Nitrogen, about 78%
💡 Group chemicals by kitchen use (salt, baking soda, vinegar), home use (washing soda, bleaching powder) and hospital use (plaster of Paris, laughing gas). Groups are easier to recall.
📝 5-question quiz on this lesson: enrol free to take it and track your score.
Biology questions cover the cell, organs of the human body, vitamins and deficiency diseases, and diseases with their causes and vaccines.
- The cell is the basic unit of life. Robert Hooke first saw cells (in cork) in 1665.
- Mitochondria are the 'powerhouse of the cell'. Ribosomes make proteins. The nucleus controls the cell and holds DNA.
- An adult human has 206 bones. The femur (thigh bone) is the longest bone; the stapes in the ear is the smallest.
- The skin is the largest organ; the liver is the largest gland. The heart has four chambers.
- Normal body temperature is about 37°C (98.6°F). Normal adult blood pressure is about 120/80 mm Hg.
- Karl Landsteiner discovered blood groups. Group O negative is the universal donor; AB positive is the universal recipient. Insulin is made by the pancreas.
- Vitamin A deficiency: night blindness. Vitamin B1: beriberi. Vitamin B3: pellagra. Vitamin B12: pernicious anaemia.
- Vitamin C deficiency: scurvy (bleeding gums). Vitamin D: rickets in children. Vitamin K helps blood clotting.
- Vitamins A, D, E and K are fat-soluble; B and C are water-soluble.
- Iodine deficiency causes goitre; iron deficiency causes anaemia.
- Protein deficiency in children causes kwashiorkor; shortage of both energy and protein causes marasmus.
- Caused by bacteria: tuberculosis, cholera, typhoid, tetanus, diphtheria. Caused by viruses: polio, measles, rabies, dengue, COVID-19.
- Malaria is caused by the Plasmodium parasite, spread by the female Anopheles mosquito. Dengue and chikungunya are spread by the Aedes mosquito.
- Kyasanur Forest Disease (KFD, 'monkey fever') is a tick-borne viral disease first found in Shivamogga district, Karnataka, in 1957.
- Edward Jenner made the first vaccine (smallpox, 1796). Louis Pasteur made the rabies vaccine. BCG vaccine protects against tuberculosis.
- Smallpox was declared eradicated worldwide in 1980. WHO certified India polio-free in 2014.
- Powerhouse of cell
- Mitochondria
- Bones in adult
- 206
- Largest gland
- Liver
- Universal donor
- O negative
- Scurvy
- Vitamin C
- Rickets
- Vitamin D
- Night blindness
- Vitamin A
- Goitre
- Iodine
- Malaria vector
- Female Anopheles
- KFD first found
- Shivamogga, 1957
💡 Learn vitamins as a chain: A-night blindness, B1-beriberi, C-scurvy, D-rickets, K-clotting. Say it aloud a few times; it sticks.
📝 5-question quiz on this lesson: enrol free to take it and track your score.
This lesson covers India's space programme (headquartered in Bengaluru), basic computer terms and major public health programmes, all common in KEA general knowledge papers.
- ISRO was set up on 15 August 1969. Its headquarters (Antariksh Bhavan) is in Bengaluru. Vikram Sarabhai is called the father of the Indian space programme.
- India's first satellite Aryabhata was launched on 19 April 1975 (by a Soviet rocket). Rockets are launched from Sriharikota, Andhra Pradesh.
- Karnataka hosts the U R Rao Satellite Centre (Bengaluru), the Master Control Facility (Hassan) and the Indian Deep Space Network (Byalalu, near Bengaluru).
- Chandrayaan-1 (2008) found evidence of water on the Moon. Mangalyaan (Mars Orbiter Mission) reached Mars orbit in 2014 on the first attempt.
- Chandrayaan-3 landed near the Moon's south pole on 23 August 2023; this day is National Space Day. Aditya-L1, the solar mission, was launched in September 2023.
- In 2025 Shubhanshu Shukla became the first Indian to visit the International Space Station (Axiom-4 mission). Gaganyaan is India's own human spaceflight programme.
- A computer works in binary (0 and 1). A bit is one binary digit; 8 bits make 1 byte; 1 kilobyte = 1024 bytes.
- The CPU is the 'brain' of the computer. RAM is temporary (volatile) memory; ROM keeps data when power is off.
- Input devices: keyboard, mouse, scanner. Output devices: monitor, printer, speaker.
- Charles Babbage is called the father of the computer. Tim Berners-Lee created the World Wide Web (1989).
- PARAM 8000 (1991) by C-DAC was India's first supercomputer. Bengaluru is called the 'Silicon Valley of India'.
- The Universal Immunisation Programme (1985) gives free vaccines to children and pregnant women. Mission Indradhanush (2014) speeds up full immunisation.
- Pulse Polio campaign started in 1995; India was certified polio-free in 2014.
- Ayushman Bharat (2018) has two parts: Health and Wellness Centres (now Ayushman Arogya Mandirs) and PM-JAY, which gives health cover up to ₹5 lakh per family per year.
- In Karnataka, PM-JAY runs together with the state scheme as Ayushman Bharat - Arogya Karnataka.
- The National Health Mission (2013) joins the rural and urban health missions.
- ISRO founded
- 15 August 1969
- ISRO HQ
- Bengaluru
- First satellite
- Aryabhata, 1975
- National Space Day
- 23 August
- Launch site
- Sriharikota
- 1 byte
- 8 bits
- Father of computer
- Charles Babbage
- Polio-free India
- 2014
- PM-JAY cover
- ₹5 lakh per family per year
💡 Keep a small list of ISRO missions with year and one key fact each. Space questions are common, and dates like 23 August 2023 are asked again and again.
📝 5-question quiz on this lesson: enrol free to take it and track your score.
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