Explanation: Vibration. Convulsions are rapid involuntary muscle contractions. Impulse is the change of momentum of an object when the object is acted upon by a force for an interval of time. Swings work by converting potential energy into kinetic energy and vice versa continuously.

Explanation: A transverse wave is a wave whose oscillations are perpendicular to the direction of wave propagation. A longitudinal wave is a wave in which the particles of the medium vibrate in the same direction, as the propagation of the wave.

Explanation: Wave speed. Wave height – the vertical distance between the trough of a wave and the following crest. Wave crest and trough – A crest point on a wave is the maximum value of upward displacement within a cycle. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.

Explanation: Infrared waves. When materials are exposed to the infrared radiation, the water molecules of the material absorb this radiation. This results in the increase of thermal motion of the water molecules in that material. This is the reason why infrared radiations are also known as heat waves.

Explanation: Radioactive energy. The process by which Earth makes heat is called radioactive decay. It involves the disintegration of natural radioactive elements inside Earth. Examples – Uranium and thorium.

Explanation: Atomic. Tokamak is a device used in nuclear-fusion research for magnetic confinement of plasma. The fusion reaction in the Tokamak will be powered with deuterium and tritium, two isotopes of hydrogen.

Explanation: Gamma rays. X-rays are also high-frequency electromagnetic radiation, but they have a lower frequency and longer wavelength than gamma rays.

Explanation: Electromagnetic telegraph. Inventions and discoveries : Henry Moseley – The atomic battery. Pierre and Marie Curie – Radium. Percy Spencer – Microwave. David Hughes and Thomas Edison – Carbon Microphone. John Bardeen, Walter Brattain and William Shockley – Transistor. Wilhelm Conrad Roentgen – X Ray. Victor Francis Hess – Cosmic radiation.

Explanation: 1887. Photoelectric effect – The emission of electrons from the surface of a metal when light is incident on it. Scientists and their discoveries : Michael Faraday – Electromagnetic Induction. Thomas Edison – Incandescent light bulb, phonograph. Albert Einstein – Theory of Relativity.

Explanation: James Watt (Inventor of steam Engine). Horsepower : Unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. It is calculated by multiplying the amount of force (in pounds) by the speed (in feet per second). 1 Hp – 746 watts (W) or 0.746 kilowatts (kW).

Explanation: Hans Christian Oersted. John Cockcroft and Ernest Walton shared the Nobel Prize (1951) in Physics for the “transmutation of atomic nuclei by artificially accelerated atomic particles”. William Gilbert – Invented the Electroscope. Heinrich Hertz – Discovered the photoelectric effect.

Explanation: Georg Simon Ohm. Ohm’s Law : Voltage (V) = Current (I) x Resistance (R). William Gilbert created the science of magnetism and discovered that the Earth is a magnet. William Watson introduced the Leyden jar. Gustav Kirchhoff and Robert Bunsen discovered two alkali metals, caesium and rubidium.

Explanation: Jean Baptiste Joseph Fourier : Discovered “Green house effect” in 1824. Louis de Broglie : He was awarded the 1929 Nobel Prize in Physics “for his discovery of the wave nature of electrons”. Joseph-Louis Lagrange : Contributed to the development of celestial mechanics, calculus, algebra, number theory, and group theory. Ernest Walton : Won the 1951 Nobel Prize in Physics with his colleague John Cockcroft for producing the first artificial nuclear disintegration in history.

Explanation: Joseph Henry, renowned for his discovery of self-inductance in electric circuits and his work on electromagnets like Albany and Yale magnets. John Cockcroft was a British physicist, who won the Nobel Prize (1951) in Physics for splitting the atomic nucleus. William Gilbert – the inventor of the term “electricity”. Edward Purcell, an American physicist, won the Nobel Prize (1952) for Physics for discovery of nuclear magnetic resonance in liquids and solids.

Explanation: Leon Foucault also discovered the Gyroscope. Famous scientists and discoveries: Nikola Tesla – AC Power (alternating current), Tesla Coil, Magnifying Transmitter. Albert Einstein – Theory of relativity and the concept of mass-energy equivalence (E = mc2 ); J.J Thomson – Electron. Ernest Rutherford (father of nuclear physics) – Discovered alpha and beta rays, set forth the laws of radioactive decay and identified alpha particles as helium nuclei. John Dalton – Theory on atoms.

Explanation: Guglielmo Marconi (Father of Radio). His Inventions – Radio (1895), Monopole Antenna, Magnetic Detector (1902). Awards – Matteucci Medal (1901), Albert Medal (1914), IEEE Medal of Honor (1920). Other engineers who got nobel prize – Wilhelm Rontgen (1901) – The discovery of X-Rays. Pieter zeeman and Hendrik Lorentz (1902) – They discovered the influence of Magnetic upon Radiation phenomena. Albert Einstein (1921) – Discovered the Law of Photoelectric Effect.

Explanation: Michelson and Morley experiment – They tried to explain that Earth moved around the sun on its orbit, and the flow of substances like ether across the Earth’s surface could produce a detectable ‘ether wind’. Maxwell and Hertz experiment – Maxwell had proved that light was an electromagnetic wave and Hertz measured Maxwell’s waves and explained that the velocity of these waves was equal to the velocity of light. Faraday and Henry Experiments – Electromagnetic Induction. Marconi used radio waves to transmit signals over several kilometers. J.J. Thomson discovered the negatively charged part of the atom (the electron).

Explanation: 1825. Michael Faraday also known as Father of Electricity. Inventions and Discoveries: Electric motor (1822), Electromagnetic induction (1831), Laws of electrolysis (1834), Liquefaction of gasses and their refrigeration (1823).

Explanation: Paul Dirac Known for “Dirac equation” related to quantum theory. Physicist Heike Kamerlingh Onnes discovered liquid Helium. Albert Einstein – Theory of relativity. Isaac Newton – Laws of motion, Gravity. Edwin Hubble – Law of Cosmic Expansion. Kepler – Laws of Planetary Motion. Archimedes – Buoyancy Principle. Heisenberg – Uncertainty Principle.

Explanation: Auguste Bravais. William Bragg : Won a Nobel Prize with his son Lawrence Bragg (1915) for their services in the analysis of crystal structure by means of X-rays. Jerome Karle : He was awarded the Nobel Prize in Chemistry in 1985, for the direct analysis of crystal structures using X-ray scattering techniques. Charles Frank : known for his work on crystal growth, liquid crystals and on the role of dislocations in crystals.

Explanation: Theory of nuclear forces. Famous Nobel Prize Awardee in Physics : 1945 – Wolfgang Pauli (“for the discovery of the Exclusion Principle, also called the Pauli Principle”); 1944 – Isidor Isaac Rabi (“for his resonance method for recording the magnetic properties of atomic nuclei”) ; 1950 – Cecil Frank Powell (“for his development of the photographic method of studying nuclear processes and his discoveries regarding mesons made with this method”).

Explanation: Andre Marie Ampere. He proposed that a current-carrying conductor creates a magnetic field, and that a magnet also exerts an equal and opposite force on the current-carrying conductor. This is known as Ampere’s law.

Explanation: eiger and Nuttall. Alpha decay spontaneously emits excessive energy by emitting the alpha particle, in which an atomic nucleus emits an alpha particle (helium nucleus) and ‘decays’ into a different atomic nucleus. Ernest Orlando Lawrence – Nobel Prize in Physics (1939) for the invention of cyclotron. Sir James Chadwick – the Nobel Prize in Physics (1935) for discovery of the neutron. William Aston – Nobel Prize in Chemistry (1922) for discovery by means of a mass spectrograph of isotopes in several non-radioactive elements. Frederick Soddy was the first to announce the concept that atoms can be identical chemically and yet have different atomic weights.

Explanation: Invention of mercury barometer. Spring Balance (a balance that measures weight by the tension of a spring) – Richard Salter. Piezometer (an instrument for measuring the pressure of a liquid or gas) – Hans Christian Oersted. Vacuum Gauge (measures pressure below the atmospheric pressure) – Marcello Stefano Pirani.

Explanation: Robert Hooke.

Explanation: Charles-Augustin Coulomb. RA Millikan determines the magnitude of the electron’s charge by Oil drop experiment (1909).

Explanation: Sir JJ Thomson (Joseph John Thomson). Andre-Marie Ampere (named the science of electrodynamics, now known as electromagnetism), Albert Einstein (1921; Photoelectric effect), and Alessandro Volta (invented the electric battery).

Explanation: Isaac Newton. Principia is a work expounding Newton’s laws of motion and his law of universal gravitation. Johannes Kepler (‘Epitome Astronomiae’), John Philoponus (‘Arbiter’), and Edmund Halley (‘The Astronomy Book’).

Explanation: Otto von Guericke. John Cockcroft and Ernest Walton developed a device, an accelerator, to generate more penetrating radiation. Enrico Fermi started the world’s first man-made nuclear reactor in 1942.

Explanation: C V Raman was awarded the 1930 Nobel Prize in Physics for his discovery of the Raman effect.

Explanation: L.E. Waterman. Alfred Nobel’s most famous invention was dynamite. Ian Donald was an obstetrician who developed ultrasound diagnostics. David Hughes invented the Carbon Microphone.

Explanation: Zeeman effect. It is named after the Dutch physicist Pieter Zeeman, who discovered it in 1896 and received a Nobel prize for this discovery.

Explanation: Faraday and Henry (1831). The principle of electromagnetic induction states that the EMF induced in a loop by a changing magnetic flux is equal to the rate of change of magnetic flux threading the loop.

Explanation: X-Rays. Wilhelm Conrad Roentgen was a German mechanical engineer and physicist who in 1895 produced and detected electromagnetic radiation in a wavelength range known as X-rays, an achievement that earned him the first Nobel Prize in Physics in 1901.

Explanation: Max Karl Ernst Ludwig Planck. Louis de Broglie (Physics 1929, discovery of the wave nature of electrons). Werner Heisenberg (Physics 1932, Creation of quantum mechanics). James Chadwick (Physics 1935, Discovery of the neutron).

Explanation: Heike Kamerlingh Onnes. Superconductivity – A phenomenon in which certain substances (conductor of electricity) offer zero resistance when it cools below some temperature level called (Tc) critical temperature. Examples of superconductors – Aluminum, Niobium, Mercury.

Explanation: Eli Whitney (In 1794). Cotton gin is a machine that revolutionized the production of cotton by greatly speeding up the process of removing seeds from cotton fiber.

Explanation: Stephanie Louise Kwolek. Stephanie Kwolek was a chemist at the DuPont company in Wilmington, Delaware, when she invented the stronger-than-steel fiber in 1965.

Explanation: Joule is the unit of work. Some other SI Units : Energy – Joule, Power – Watt, Force or Weight – Newton, Frequency – Hertz, Resistance – ohm. Seven Fundamental quantities with their units: Length (meter), Mass (kilogram), Time (second), Electric current (ampere), Thermodynamic temperature (kelvin), Amount of substance (mole), Luminous intensity (candela).

Explanation: Volume – Meter. SI Units : Volume – cubic metre. Length – metre (m). Mass – kilogram (kg). Time – second (s). Amount of substance – mole. Luminous intensity – candela (cd). Electric current – ampere (A). Thermodynamic temperature – kelvin (K). Frequency – hertz (Hz). Electric charge – coulomb (C). Electric potential (Voltage) – volt (V). Inductance – henry (H). Capacitance – farad (F). Resistance – ohm (Ω). Electrical conductance – siemens (S). Magnetic flux density – tesla (T). Power, Radiant flux – watt (W). Angle – radian (rad).

Explanation: 3600 KJ/h. 1 kilowatt-hour is defined as the energy consumed by a device of power 1 kilowatt in 1 hour. A kilowatt is a unit of Electric Power. 1Kw is 1000 watts. Watt = Joule/Second. 1 Horsepower = 746 watts.

Explanation: Stokes (St) (physicist Sir George Gabriel Stokes). Viscosity is defined as the quantity that represents a fluid’s resistance to flow. It describes the internal friction of a moving fluid. A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction. SI Unit of Viscosity – Pascal second (Pa·s) or kg·m-1s -1 . Kinematic viscosity – m2/s.

Explanation: kg m/s. Linear momentum is the vector quantity and defined as the product of the mass of an object (m) and its velocity (v). Units and Measurements : Temperature – kelvin, Electric current – ampere, Luminous intensity – candela, Plane angle – radian and Solid angle – steradian.

Explanation: Distance and Speed. Scalar Quantity – Quantities with magnitude only, it does not depend on direction. Examples : Temperature and Mass. Vector Quantity – Quantities with both magnitude and direction. Examples : Displacement, Velocity and Acceleration.

Explanation: Gravitational Intensity – Unit (N/kg), Formula ( ), Dimensional 𝐹𝑜𝑟𝑐𝑒 𝑚𝑎𝑠𝑠 Formula [𝑀 ]. Vector Quantity – The 0 𝐿 1 𝑇 −2 physical quantity that has both direction as well as magnitude. Examples – Displacement, velocity, Acceleration, Force. Scalar Quantity – The physical quantity that has only magnitude, no direction. Examples – Length, Temperature, Direction, Speed, mass.

Explanation: Four. First rule is that all non-zero digits are considered as significant. The second rule is that Zeros between non-zero digits are also considered as significant. Example – 4.5006 has five significant figures. The third rule can be given as, Zeroes at the end or on the right side of the number are also significant. Example – 0.500 has three significant figures.

Explanation: [MLT-2]. Force (Newton) – A push or pull on an object that produces acceleration in the body on which it acts. Other Physical Quantity – Acceleration [L 𝑇 ], Electric Capacitance [ ], −2 𝑀 −1 𝐿 −2 𝑇 4 𝐼 2 Energy [𝑀𝐿 ], Power [ ], Electric 2 𝑇 −2 𝑀𝐿 2 𝑇 −3 Field Strength [𝑀𝐿𝑇 ]. −3 𝐼 −1

Explanation: Earthquakes. Richter scale – It is used to measure the magnitude of earthquakes. Instruments and Uses : Udometer (Amount of liquid precipitation), Anemometer (wind speed), Barometer (Atmospheric pressure), Hygrometer (humidity), Lactometer (Purity of milk), Venturimeter (Flow rate of liquid in a pipe), Altimeter (Altitude), Manometer (Pressure in pipes).

Explanation: Luminance. One lux is the amount of illumination provided when one lumen is evenly distributed over an area of one square meter. The candela is the unit of luminous intensity.

Explanation: Doppler weather radar (weather surveillance radar); Designed and developed by – ISRO and Manufactured by – Bharat Electronics Limited (BEL), Bengaluru. Barometer – Measures atmospheric pressure; invented by Evangelista Torricelli (1643). Spectral Pyranometer- Measures solar irradiance on a planar surface; 2D Sonic Anemometer – Detects the horizontal component of the wind speed and wind direction.