*The branch of science concerned with the nature and properties of matter and energy Ans : Physics *Branches of physics are Dynamics,Thermody namics, Mechanics, Optics, Acoustics, Electronics, Astrophysics, Nuclear physics.
*Anything that possesses weight and occupies space is - Matter *7 states of matter Solid, Liquid, Gas, Plasma, Bose Einstein Condensate, Fermionic condensate, Quark Gluon Plasma. *Matter that has definite shape and volume Ans : Solid *Matter that doesn’t have definite shape, but has definite volume - Liquid *Matter that doesn’t have definite shape and volume, but occupies the shape of container Ans : Gas *Fourth state of matter - Plasma *Fifth state of matter - Bose-Einstein Condensate *At ultra high temperature matter exist in plasma form. *Molecules are seen in most irregular form in Plasma State. *99% of matter in the universe is in plasma form. *Theory of classification of fundamental particles and how they interact is known as Ans : Standard Model Elementary Particles Fermions Bosons
Quarks Leptons Gauge Bosons
*Number of elementary fermions in standard model -12 *Any particle made up of Quarks and Gluons are called as Hadrons *Hadrons are categorized into two Ans : Mesons and Baryons *Massive particles which are made up of quark -Antiquark pair are called Ans : Mesons *Exchange particle in Quark-Quark interaction Ans : Gluon *Any Particle which are made up of 3 quarks Ans : Baryons *The most stable form of hadrons are Ans : Protons and Neutrons *The term ‘God Particle’ was first coined by Ans : Leon Lederman *The term ‘Boson’ was first coined by Ans : Paul Dirac *The word ‘quark’ was coined by Ans : Murray Gell Man *Quark model of matter was discovered by Ans : Murray Gellman and George Swieg *Bose - Einstein condensate was first predicted by Ans : Sathyendra Nath Bose and Albert Einstein *The ‘pure’ Bose - Einstein condensate was first created by Ans : Eric Cornell and Carl Wieman *A super fluid phase formed by bosonic atoms is known as Ans : Bose-Einstein Condensate *A Superfluid phase formed by fermonic particles Ans : Fermionic Condensate *Equipment used by the scientist to create Higgs boson and other particles for observation and study Ans : LHC (Large Hadron Collider) *Worlds largest and highest energy particle accelerator Ans : LHC (27 Kms in Circumference) *LHC is located in Ans : Geneva (Switzerland) *LHC is operated by Ans : CERN *CERN is a European Organization for Nuclear Research *Purpose of LHC Experiment - To investigate and understand why there is a diversity of life in the Universe.
*Energy carriers in the matter are known as Ans : Bosons *Bosons which carry electro magnetic force Ans : Photons *Bosons which carry weak nuclear force Ans : W&Z Bosons *Bosons which carry strong nuclear force Ans : Gluons *Particle which gives the property of mass to the matter is Ans : Higgs Boson *Fundamental particle which is known as God Particle Ans : Higgs Boson *Particle which is considered as the buiding blocks of all life Ans : Higgs Boson (discovered at CERN in 4th July 2012)
Units and Measurements
*Units are of two types 1. Fundamental units 2.Derived units Fundamental units *Fundamental units are the units of fundamental quantities which can’t be derived from any other quantities like Length, Mass and Time. *Fundamental units can be expressed in three kinds of measuring systems such as CGS, MKS and FPS. *FPS is also known as British System of Units. *The unit of Time is same in all the Systems.
*Length-Centri meter -Metre-Foot *Mass-Gram-Kilogram -Pound *Time-Second-Second-Second
7 base units in SI system
*Base quantity Name Symbol *Length -metre -m *Mass -kilogram -kg *Time -second -s *Electric current -ampere -A *Temperature -kelvin -K *Amount of substance -mole -mol *Luminous intensity -candela -cd
*Derived Units are the units which are derived from the fundamental units. eg: Speed, Area, Acceleration etc. *In general, Physical quantities are divided into two classes. 1.Scalar quantities 2. Vector quantities *A physical quantity that has only magnitude, but no direction is known as - Scalar quantity eg: Mass, Length, Time, Volume, Speed, Energy, Work, Pressure, Density etc. *A physical quantity that has both magnitude and direction is known as - Vector quantity eg: Velocity, Momentum, Force, Acceleration, Displacement, Torque etc.
Work, Energy, Power
*A work is said to be done if there is a displacement of the body on which force is acted, in the direction of the force applied. *The work done by a force is given by area of force-displacement graph. *A man pushes a metal block and fails to it He does - no work at all *W = Fxd ‘F’ - Force applied 'd’ - Distance which object is displaced ‘W' -'Work done by the force
*Ability of a body to do work - Energy Unit of work: Joule or Nm (Newton metre) *In CGS, the unit of work is erg 1 Joule = 107erg *The term ‘Energy’ was first coined by - Thomas Young. Albert Einstein *Law of Conservation of Energy was put forwar d by Ans : Albert Einstein. *According to law of conservation of energy, energy can neither be created nor be destroyed but can be transformed from one form to another. *Einstein proposed special theory of Relativity in 1905. *Einstein proposed General theory of relativity in 1915. *E = mc2 is known as the mass - energy equivalence which shows the relation between matter and energy.
Potential Energy & Kinetic Energy
*Energy of an object occurred due to its motion Ans : Mechanical energy *Mechanical energy is of two forms, 1. Potential energy 2. Kinetic energy *The energy possessed by a body by virtue of its position is Ans : Potential Energy (P.E). *For a body of mass ‘m’ situated at a height ‘h’ above the ground, P.E. = mgh ‘g' federation due to gravity. m - mass h-height *Energy stored in the water-reservoir of a dam Ans : Potential energy *Energy stored in a compressed spring Ans : Potential energy *Potential energy of an object at rest on ground Ans : Zero *Potential energy increases as the height Ans : increases. *For an object thrown vertically upwards potential energy increases and kinetic energy decreases. *Potential energy of an object will always be possessed above the level of earth’s surface. For a freely falling object potential energy decreases as it approaches earth. *The energy possessed by a body due to its motion is Ans : Kinetic Energy (K.E.) *For a body of mass ‘m’ moving with a velocity V, K.E. = V2 mv2 m = mass, v = velocity *If the velocity of an object is doubled, its kinetic energy becomes four times. *If the mass of a moving body is doubled, its Kinetic energy is also doubled. *A moving bullet or a moving stone possesses Kinejic energy. *Kinetic energy is always positive. *Law of conservation of momentum is used in the application of rocket propulsion, jet engine, firing of a pistol etc.
*The rate of doing work is known as Power. Power (P) = Work done / Time *Unit of measurement of power is - Horse power *Joule /sec= 1 watt *1 horse power = 746 watts *1 kilowatt = 1000 watts *1 megawatt =1000000 watts
*When an object falls towards the earth under gravity in the absence of air resistance is called freely falling body. *All objects in free fall near the earth have same acceleration. *The acceleration of an object in free fall is independent of its Ans : Mass
*Terminal Velocity is the highest velocity attainable by an object as it falls through air. *At some speed, the force of resistance will be equal to the gravitational pull on the object. At this point the object ceases to accelerate and continues falling at a constant speed is called terminal velocity.
*The flow of electrons is Ans : Electricity *Properties of Electricity Ans : Electric charge, Electric current, Electric field, Electric potential, Electro magnetism *Electric charge was first observed in a substance called Ans : Amber *Fundamental quantity of electricity Ans : Charge *Unit of electric charge Ans : coulomb *1 coulomb = 6.25 x 1018 electrons *Charge of an electron is 1.6 x 10-19C *Electric current is the flow of electrically charged particles through a medium. Current = Charge/Time *Unit of flow of electric current - Ampere. *Electric field is the region which surrounds the electrically charged particles.
*Father of Electricity Ans : Michael Faraday *Law of electrolysis was formulated by Ans : Michael Faraday *The concept of an electric field was introduced by Ans : Michael Faraday *Dynamo was invented by Ans : Michael Faraday *Electro magnetic Induction was discovered by Ans : Michael Faraday *Electrolysis is the process of splitting up of a chemical substance when an electric current flows through it. *Substance used for electrolysis are - electrolytes. eg: Sodium Chloride, Potassium Chloride, Hydrochloric acid. *Electrical conductivity of an electrolyte increases with the rise in temperature. Instrument that regulates the resistance or current in a circuit - Rheostat *Electric potential is the capacity of an electric field to do work on an electric charge. *Electro magnetism is the force that causes the interaction between the magnetic field and the electrically charged particles. *Electro magnetism was discovered by Hans Christian Oersted (1820). *Negatively charged particles gain electrons. *Positively charged particles lose electrons. *The stationary electric charge built up on a material is called Ans : Static Electricity. *Electricity that can flow from one point to another through the conductors, cables etc. is called Ans : Dynamic Electricity (current electricity) *Dynamic electricity is of two types. 1.Alternating current (AC) 2.Direct Current (DC) *Alternating current (AC) is the continuous How of current. *It reverses its direction and magnitude with respect to time. *Direct Current (DC) is the unidirectional flow of electric charge. *It does not reverse its direction with respect to time. *Batteries, solar cells, thermocouples etc produce DC. *DC was formerly known as Galvanic current. *AC is used more widely than DC. *The advantage of AC over DC is, it can be transmitted over long distances with minimum power loss. *The device which conducts DC but blocks AC is Inductor.
Conductors and Insulators
*The substances which easily allows electricity to flow through them is called Conductors, eg: Metals, graphite, animal bodies and earth. *The best conductor of electricity is Silver, as it has the least resistance. *Copper and Aluminium are the metals commonly used in electrical circuits.
*Electric Fan -Electrical to Mechanical energy *Electric bell -Electrical to Sound energy *Solarcell -Solar to Electrical energy *Electric bulb -Electrical to Light energy and Heat energy *Battery -Chemical to electric energy *Electric oven -Electrical to Heat energy *Dynamo-Mechanical to Electrical energy *Motor-Electrical to Mechanical energy *Lightning conductor was invented by Ans : Benjamin Franklin *The liquid which conducts electricity but does not undergo electrolysis is Ans : Mercury. *Salt water conducts electricity depending on the concentration of dissolved salts. *Substance which does not allow the flow of current through them is called - insulator eg: Glass, dry wood, dry paper, plastics, porcelain, mica, rubber, nylon, dry air etc. *The commonly used insulator in electrical systems is porcelain or glass. *The substance which partially conduct electricity is called - semiconductors. eg: Germanium, Silicon
*Resistance opposes the flow of electric current in a circuit. *Resistivity is the opposite of conductivity. *Conductivity is inversely proportional to the resistance. ie; 1 siemens = 1/ ohm-1 = mho *A filament of 60W bulb is thinner than the filament of 10GW bulb. *If two bulbs of 60 W and 100W are connected in parallel, then the 100W bulb will glow more. *If two bulbs of 60W and 100W are connected in series, then the 60W bulb will glow, more because the resistance of 60W bulb is more than that of 100W bulb.
*At very low temperature most of the metals, allow current to pass freely through them. This phenomenon is called superconductivity and such materials are called super conductors. *Super conductivity was discovered by the Dutch Physicist Heike Kamerlingh Onnes. *Super conductors possess zero resistance at very low temperature. *Ceramics is a superconductor above 100 K.
Electrical Power Transmission
*Most widely used current in domestic purposes is AC *Electricity for domestic purpose is measured in Kilowatt hour (KWh) and are commonly called as ‘units’-lKWh = 1000 watt x 3600 seconds. *KWh is also used as the commercial unit of electrical energy *Electric power transmission was developed by Thomas Alva Edison. *The supply voltage produced in India is 11 KV (Kilo Volt) or 11,000 volt. *Voltage of electricity supplied for houeshold use in India 220-230 volt *The frequency of household electric current in India is 50 Hertz *Instrument that measures the amount of electric energy used by a consumer - Watt hour meter (Electricity meter) * In houses, electric wirings are connected in parallel because all the instruments in the house could get equal supply of electricity and stronger current for longer time.
*A protecting device, which cuts off an electric circuit when high current flows through the wire Ans : Fuse *In an electric circuit, a fuse is connected in the live wire to avoid overloading. *Copper or the alloy of Tin and Lead are the metals used in an ordinary fuse wire. *A fuse wire is characterized by Ans : High resistance & low melting point. *Short circuiting is a high current produced in a low resistance circuit when two wires of main comes in contact with each other. *When a charged body is connected to the earth it gets neutralised. This is called earthing. *Electric fittings are earthed to prevent electric shock. *MCB - Miniature Circuit Breaker (a small trip switch that stops the flow of electric current in an overloaded electric circuit). *ELCB - Earth Leakage Circuit Breaker (safety device used in electrical installation with high Earth impedence to prevent shock). *The earthwire and the fuse together protect the user and the electrical appliances *Quartz crystal in watches work on the principle of peizo electricity. *A cell uses chemical reaction to make electricity. *A number of cells connected together are called battery. *The negative electrode in a dry cell is cathode, eg: Zinc * The positive electrode in a dry cell is anode, eg: carbon rod. *The electrical device which is used to increase or decrease the amount of AC voltage between two circuits is - Transformer. *Colour of positive wire in domestic circuits Ans : Red/brown *Colour of neutral wire in domestic circuits Ans : Black / blue *Colour of earth wire in domestic circuits Ans : Green
*EMF (Electro Motive Force) or potential difference measured in volt is called voltage. *The emf of a dry cell (torch cells, remote controls etc.) is 1.5 volts. *The emf of a voltaic cell is 1 volt. *Voltage of a. torch cell -1.5 volt. *Battery used in mobile phones - Lithium - ion battery (3.6 volt)
*The process of production of voltage (emf) across a conductor moving through a magnetic field is called electromagnetic induction. *Generators (Dynamo), Motors, Transformers, Microphones, Induction coil and Solenoids work on the principle of Faraday’s law of electro magnetic induction.
*Phenomenon of inducing a voltage (emf) in a coil by changing current in neighbouring coil is known as Mutual Induction. *The coil in which voltage is induced is called secondary coil *The coil in which current is changed is called Primary Coil. *Instruments work on the principle of mutual induction - Transformers, Generators etc. *Electric device that converts mechanical energy into electrical energy - Electric generator.
*Incandescent lamps are filament lamps (Bulbs). *Electric Bulb was discovered by Ans : Thomas Alva Edison. *Gas used to fill a filament lamp Ans : Argon, Nitrogen etc. *Lamp having highest energy efficiency Ans : LED ' Lamp . *In Fluorescent lamp, mixture of Mercury and Argon gas are filled. *Examples of discharge lamps - Compact Fluorescent lamp (CFL), Tube lights, Vapour lamps * Lifespan of filament lamp - 1000 hours ‘ *Lifespan of fluorescent lamps - 5000 hours *Lamps used in advertisement boards - Neon vapour lamps *The material used for making filament of bulb is Tungsten (W). *Characterstics of LED, when compared to other lamps are energy efficient, low cost, longer life time, small size. *Energy efficient means low consumption of energy. *Nickel and Cadmium are used as electrodes in rechargable batteries of electric shaver, flash lights etc. *Polygraph test machine detects and records the electrical variations in the body when a person tells lies. *Electricity produced through water is termed as ‘Hydro Power’. *Hydroelectric power is an electrical energy obtained from water-power which is used to drive a dynamo. *National Energy Conservation Day? Ans : December 14 *The purpose of Choke in the tube light is Ans : to increase the voltage momentarily
Vapour Lamps & Colours
*Chlorine Vapour Lamp -Green *Nitrogen - Red *Hydrogen - Blue *Sodium - Yellow *Neon - range *Mercury - White
ELECTRONICS & TELECOMMUNICATION
*The study of the behaviour of electrons, their control and use is known as Electronics. *An electronic device which has the semiconducting property that allows current to flow in one direction only -Diode *The simplest form of a vacuum tube is diode. *The emission of electrons from a strongly heated surface is called Thermionic emission. *Vacuum tubes or valves work on the principle of - Thermionic emission. *A thermionic valve having three electrodes namely cathode, anode and grid is known as Triode. *Now-a-days thermionic valves are completely replaced by Transistors *Wonder Baby of Electronics - Transistor *Semiconductor device used to amplify or *switch electronic signals and electrical power -Transistor *Transistor was invented by John Bardeen, W.H. Brattain, and William Shockley. *Triode was invented by Lee De Forest. *The concept of radio transmission was first demonstrated by the famous Indian scientist Ans : J.C. Bose
*Material whose conductivity falls between conductor and insulator Ans : Semiconductor *Semi conductors in their pure state are called intrinsic semiconductors *In intrinsic semicdnductors, number of holes is equal to number of electrons. *The process of adding controlled impurities to a pure semiconductor is known as doping. *The impurities which change its electrical property are called dopants. *Examples for dopants - arsenic, gallium *Doping improves the conductivity of a semi conductor. *An intrinsic semiconductor doped with impurity is known as extrinsic semh conductor. *Extrinsic semiconductors are of two types : 1.N- type semiconductor 2.P-type semiconductor *The charge carriers in N-type semiconductor Ans : Free electrons *The charge carriers in P-type semiconductors Ans : Holes. *Semi conductors are used in Photovoltaic cells (solar cells), diodes, transistors and integrated circuits (IQ. *Diode is mostly used to convert AC to DC. So a diode functions as a rectifier. *Zener dioide is used as a voltage regulator device which maintains a constant voltage. *ELINT is the Electronic Intelligence. *Semiconductors which can be used in Solar cells Ans : Silicon. *A very large number of components like diodes, transistors, condensers of capacitors and resistors are incorporated in a single chip. *A device used to store electric charge consisting of one or more pairs of conductor separated by an insulator Ans : Capacitor
*IC is an electronic circuit on semiconductor chip. *IC is made of germanium or silicon. *IC chips using Germanium was invented by Ans : Jack Kilby *IC chip using silicon was invented by Ans : Robert Noyce
*Study of light - Optics *Speed of light - 3 X 108 m/s *Time taken by Sun light to reach earth Ans : 8 minute 20 seconds (500 Seconds) *Time taken by moonlight to reach earth Ans : 1.3 seconds *Light travels fastest in Ans : Vacuum *The medium in which density of light isminimum Ans : Vacuum *What tefpens to velocity of light asit travels from , a denser medium to rarer medium Ans : Increases *Light is a transverse wave. *Unit of wavelength of light Ans : Angstrom *Speed of Light Was first measured by Ans : Ole Christian Romer *The medium in which the speed of light is least Ans : Diamond *The medium in which density of light is maximum Ans : Diamond *Particle which travels faster than light- Ans : Tachyons *Tachyons were discovered by- Ans : ECGSudarsan *The Scientist who proved that light is an electro magnetic wave Ans : Henrich Hertz *Order of speed of light in different medium is - glass < water < air < vacuum *Substance which do not pass light through them are called Ans : Opaque substances eg:- Cardboard, stone *Substance which allow light to pass through them Ans : Transparent substances eg:- glass *Substance which allow a part of incident light to pass through them - Translucent substances eg:- oil paper *Rainbow is always formed in the opposite direction of sun *The direction in which the rainbow is formed in morning Ans : West
*The distance travelled by light in one year Ans : Light Year *Unit used to measure the largest distance between stars Ans : Light Year *L light year Ans : 9.46*10^12Km *I Parsec Ans : 3.26 light year *The distance from sun to the nearest star Ans : 4 1/2 light year
*The phenomenon of emission of electrons from a metal surface coated by sodium or potassium when light rays falls on it is called Ans : photoelectric effect. *Photoelectric effect was proposed by Ans : Henrich Hertz. *Photoelectric effect was explained by Ans : Albert Einstein. *The law of photo electric effect was formulated by Ans : Albert Einstein *Albert Eienstein won the Nobel prize in 1921 for the scientific explanation of photo electric effect. *Einstein explained the photo electric effect on the basis of quantum theory *The phenomenon, photo electric effect cannot be explained on the basis of electro magnetic theory. *The colour of sky in moon Ans : Black *When a red flower is observed through blue glass plate, it appears,as Ans : Black *Colour of green leaf in red light Ans : Black *Colour which is very sensitive to human eye Ans : Yellow *Colour which is used in danger signals Ans : Red (Because it has longest wavelength) *Colours used in scientific laboratory for indicating danger Ans : Yellow *The colour used in fog lamp of vehicles Ans : Yellow Light
*Quantum theory was put forwarded by Max Planck. *Quantum theory states that the light rays consist of small energy packets called quantum. *According to quantum theory, quantum of , light is known as a photon. *Phenomenon of emission of light from substances after the absorbtion of photons is called Photoluminescence.
*Colour having minimum wavelength Ans : Violet * Colour having maximum wavelength Ans : Red *Colour having minimum frequency Ans : Red *Colour having maximum frequency Ans : Violet *Light that scatters most Ans : Violet *Light that scatters least Ans : Red *The colour which reflects all other colours Ans : White *The colour which absorbs all other colours Ans : Black *The colour which absorbs maximum heat Ans : Black *The colour which absorbs minimum heat Ans : White *The colour which appears on the upper portion of the rainbow Ans : Red *The colour which appears on the lowest portion of rainbow Ans : Violet *Number of colours in visible light Ans : 7 (VIBGYOR - Violet, Indigo, Blue, Green, Yellow, Orange, Red) *Primary Colours Ans : Red, Blue, Green *Secondary Colours Ans : Yellow, Magenta, Cyan *Primary colours used in colour television Red, Blue, Green *Primary colour pigments used in printing Ans : Yellow, Magenta, Cyan *Colours obtained by mixing any two primary colours Ans : Secondary Colours *Green Red -> Yellow *Blue Red -> Magenta *Green Blue -> Cyan *Any two colours which combine together to form white colour is called as Complementary colours *Complementary Colours *Green Magenta ll White *Red Cyan ->White *Blue Yellow ->White *Combining three primaiy colours Red, Blue and Green, we get - White ie, RedBlueGreen -» White *The distance between Sun and Earth is generally expressed in Ans : Astronomical Unit *Wavelength of visible light Ans : 400 - 700 nanometer *‘Blue colour of the Sky’ was explained by Ans : Lord Rayleigh *‘Blue Colour of the Sea’ was explained by Sir. Ans : C.V. Raman *Photo Electric effect was discovered by Ans : Henrich Hertz *Photo Electric effect was explained by Ans : Albert Einstein
*Corpuscular theory of Light was proposed by Ans : Isaac Newton *Wave theory of Light was proposed by Ans : Christian Huygens *Scientist who discovered that Sunlight consists of 7 Colours Ans : Isaac Newton *Scientist who discovered that ‘The light travels fastest in Vacuum’ Ans : Leon Foucault *The principle of Three Primary Colours was proposed by Ans : Thomas Young *The Scientist who discovered that constituent colours join together to form composite light Ans : Isaac Newton *Electromagnetic wave theory was formulated by Ans : James Clerk Maxwell' *First accurate measurment of speed of light was made by Ans : Ole Christian Romer *Scientist who proved that light is an electro magnetic wave Ans : Henrich Hertz *Tachyon is the particle which is supposed to travel fester than light and was discovered by an Indian Scientist Ans : E.C.G. Sudharshan
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