भौतिक विज्ञान शब्दावली

भौतिक विज्ञान शब्दावली


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Physics glossary

हिन्दीअंग्रेज़ीपरिभाषा
Y अक्ष से दूरीabscissaThe value corresponding to the horizontal distance of a point on a graph from the Y axis. The X coordinate.
शुद्ध विचलनabsolute deviation
शुद्ध त्रुटिabsolute errorThe actual difference between a measured value and its accepted value.
परम शून्य तापabsolute zeroThe temperature of a body at which the kinetic energy of its molecules is at a minimum; OoK or -273.16 oC.
अवशोषण स्पेक्ट्रमabsorption spectrumA continuous spectrum interrupted by dark lines or bands that are characteristic of the medium through which the radiation has passed.
त्वरणaccelerationTime rate of change of velocity.
ग्राहीacceptorAn element with three valence electrons per atom which when added to a semiconductor crystal provides electron "holes" in the lattice structure of the crystal.
शुद्धिaccuracyCloseness of a measurement to the accepted value for a specific physical quantity; expressed in terms of error.
adhesionThe force of attraction between unlike molecules.
रुद्दोष्म प्रक्रमadiabatic processA thermal process in which no heat is added to or removed from a system.
अल्फा कणalpha particleA helium-4 nucleus, especially when emitted from the nucleus of a radioactive atom.
प्रत्यावर्ती धाराalternating currentAn electric current that has one direction during one part of a generating cycle and the opposite direction during the remainder of the cycle.
धारामापीammeterAn electric meter designed to measure current.
एम्पीयरampereThe unit of electric current; one coulomb per second.
आवर्धकamplifierA device consisting of one or more vacuum tubes (or transistors) and associated circuits, used to increase the strength of a signal.
आयामamplitudeThe maximum displacement of a vibrating particle from its equilibrium position.
आपतन कोणangle of incidenceThe angle between the incident ray and the normal drawn to the point of incidence.
परावर्तन कोणangle of reflectionThe angle between the reflected ray and the normal drawn to the point of incidence.
अपवर्तन कोणangle of refractionThe angle between the refracted ray and the normal drawn to the point of refraction.
एंग्सट्रामAngstromA unit of linear measure equal to 10(1)0 m.
कोणीय त्वरणangular accelerationThe time rate of change of angular velocity.
कोणीय आघातangular impulseThe product of a torque and the time interval during which it acts.
कोणीय संवेगangular momentumThe product of the rotational inertia of a body and its angular velocity.
कोणीय वेगangular velocityThe time rate of change of angular displacement.
धनाग्रanode(1) The positive electrode of an electric cell. (2)
प्रतिपदार्थantimatterA substance composed of antiparticles.
प्रतिकणantiparticleA counterpart of a subatomic particle having opposite properties (except for equal mass).
द्वारकapertureAny opening through which radiation may pass. The diameter of an opening that admits light to a lens or
आभासी शक्तिapparent powerThe product of the effective values of alternating voltage and current.
arc tangentThe inverse function to the tangent. Symbol: arctan or tan-l. Interpretation: "An angle whose tangent is
आर्मेचरarmatureA coil of wire formed around an iron or steel core that rotates in the magnetic field of a generator or motor.
परमाणुatomThe smallest particle of an element that can exist either alone or in combination with other atoms of the same or other elements.
परमाणु द्रव्यमान इकाईatomic mass unitOne-twelfth of the mass of carbon(1)2, or 1.6605655 x 10–27 kg.
परमाणु क्रमांकatomic numberThe number of protons in the nucleus of an atom.
परमाणु भारatomic weightThe weighted average of the atomic masses of an element's isotopes based on their relative abundance.
श्रब्य संकेतaudio signalThe alternating voltage proportional to the sound pressure produced in an electric circuit.
माध्य वेगaverage velocityTotal displacement divided by elapsed time.
प्रेरित विद्युत वाहक बलback emfAn induced emf in the armature of a motor that opposes the applied voltage.
बैंड स्पेक्ट्रमband spectrumAn emission spectrum consisting of fluted bands of color. The spectrum of a substance in the molecular state.
दाबमापीbarometerA device used to measure the pressure of the atmosphere.
बैरियानbaryonA subatomic particle with a large rest mass, e.g., the proton.
मूल समीकरणbasic equationAn equation that relates the unknown quantity with known quantities in a problem.
वैद्युत स्थितिकी का आधरभूत नियमbasic law of electrostaticsSimilarly charged objects repel each other. Oppositely charged objects attract each other.
किरण-पुंजbeamSeveral parallel rays of light considered collectively.
स्पन्दनbeatThe interference effect resulting from the superposition of two waves of slightly different frequencies propagating in the same direction. The amplitude of the resultant wave varies with time.
बेकुरलbecquerelThe rate of radioactivity equal to one disintegration per second.
बीटा कणbeta particleAn electron emitted from the nucleus of a radioactive atom.
बीटाट्रानbetatronA device that accelerates electrons by means of the transformer principle .
bevatronA high-energy synchrotron.
बंधक ऊर्जाbinding energyEnergy that must be applied to a nucleus to break it up.
क्वथनांकboiling pointThe temperature at which the vapor pressure of a liquid equals the pressure of the atmosphere.
बोसानbosonA subatomic particle with zero charge and rest mass, e.g., the photon.
बायल का नियमBoyle's lawThe volume of a dry gas varies inversely with the pressure exerted upon it, provided the temperature is constant.
ब्रीडर रिएक्टरbreeder reactorA nuclear reactor in which a fissionable material is produced at a greater rate than the fuel is consumed.
ब्राउनी गतिBrownian movementThe irregular and random movement of small particles suspended in a fluid, known to be a consequence of the thermal motion of fluid molecules.
बबल चेंबरbubble chamberInstrument used for making the paths of ionizing particles visible as a trail of tiny bubbles in a liquid.
कैलोरीcalorieThe quantity of heat equal to 4.19 joules.
उष्मामापीcalorimeterA heat-measuring device consisting of nested metal cups separated by an air space.
केंडिलcandleThe unit of luminous intensity of a light source.
धारिताcapacitanceThe ratio of the charge on either plate of a capacitor to the potential difference between the plates. capacitive reactance. Reactance in an a-c circuit containing capacitance which causes a lagging voltage.
संधारित्रcapacitorA combination of conducting plates separated by layers of a dielectric that is used to store an electric charge.
सूक्ष्म नलिकाcapillarityThe elevation or depression of liquids in small-diameter tubes.
ऋणाग्रcathode(1) The negative electrode of an electric cell. (2)
कैथोड किरणेंcathode raysParticles emanating from a cathode; electrons.
सेल्सियस पैमानाCelsius scaleThe temperature scale using the ice point as 0o and the steam point as 100o, with 100 equal divisions, or degrees, between; formerly the centigrade scale.
वक्रता केन्द्रcenter of curvatureThe center of the sphere of which the mirror or lens surface forms a part.
गुरुत्व केन्द्रcenter of gravityThe point at which all of the weight of a body can be considered to be concentrated.
अपकेन्द्रीय बलcentrifugal forceForce that tends to move the particles of a rotating object away from the center of rotation.
अभिकेन्द्रीय त्वरणcentripetal accelerationAcceleration directed toward the center of a circular path.
अभिकेन्द्रीय बलcentripetal forceThe force that produces centripetal acceleration.
शृंखला अभिक्रियाchain reactionA reaction in which the material or energy that starts the reaction is also one of the products and can cause similar reactions.
चार्ल का नियमCharles' lawThe volume of a dry gas is directly proportional to its Kelvin temperature, providing the pressure is constant.
रासायनिक परिवर्तनchemical changeA change in which new substances with new properties are formed.
रासायनिक तुल्यांकchemical equivalentThe quantity of an element, expressed in grams, equal to the ratio of its atomic weight to its valence.
वर्ण विपथनchromatic aberrationThe nonfocusing of light of different colors.
वृत्तीय गतिcircular motionMotion of a body along a circular path.
क्लाउड चेंबरcloud chamberA chamber in which charged subatomic particles appear as trails of liquid droplets.
क्षेत्रीय प्रसार गुणांकcoefficient of area expansionThe change in area per unit area of a solid per degree change in temperature.
आयतन प्रसार गुणांकcoefficient of cubic expansionThe change in volume per unit volume of a solid or liquid per degree change in temperature.
रेखीय प्रसार गुणांकcoefficient of linear expansionThe change in length per unit length of a solid per degree change in temperature.
सर्पीघषण गुणांकcoefficient of sliding frictionThe ratio of the force needed to overcome sliding friction to the normal force pressing the surfaces together.
अनुनादcoherenceThe property of two wave trains with identical wavelengths and a constant phase relationship.
cohesionThe force of attraction between like molecules.
वर्णcolorThe visual perception of light associated with its frequency or wave length.
प्रत्यावर्तकcommutatorA split ring in a d-c generator, each segment of which is connected to an end of a corresponding armature loop.
पूरक वर्णcomplementary colorsTwo colors that combine to form white light.
पूर्ण कम्पनcomplete vibrationBack-and-forth motion of an object describing simple harmonic motion.
घटकcomponentOne of the several vectors that can be combined geometrically to find a resultant vector.
बलों का संयोजनcomposition of forcesThe combining of two or more component forces into a single resultant force.
दाबनcompressionThe region of a longitudinal wave in which the distance separating the vibrating particles is less than their equilibrium distance.
अवतलconcaveSurface with center of curvature on the same side as the observer.
अवतल लेंसconcave lensA lens that diverges parallel light rays (assuming the outside refractive index to be smaller).
अवतल दर्पणconcave mirrorA mirror that converges parallel light rays incident on its surface.
एकबिन्दुगामी बलconcurrent forcesForces with lines of action that pass through the same point.
संघननcondensationThe change of phase from a gas or vapor to a liquid.
चालकताconductanceThe reciprocal of the ohmic resistance.
चालकconductorA material through which an electric charge is readily transferred.
संरक्षी बलconservative forcesForces for which the law of conservation of mechanical energy holds true; gravitational forces and electrostatic forces.
सतत स्पेक्ट्रमcontinuous spectrumA spectrum without dark lines or bands or in which there is an uninterrupted change from one color to another.
अभिसारी लेंसconverging lensA lens that is thicker in the middle than it is at the edge and bends incident parallel rays toward a common point.
उत्तलconvexSurface with center of curvature on the opposite side from the observer.
उत्तल लेंसconvex lensA lens that converges parallel light rays (assuming the outside refractive index to be smaller). convex mirror. A mirror that diverges parallel light rays incident on its surface.
ब्रम्हाण्ड किरणेंcosmic raysHigh-energy nuclear particles apparently originating from outer space.
कास्मोट्रान्cosmotronA high-energy synchrotron.
कूलाम्बcoulombThe quantity of electricity equal to the charge on 6.25 x 1018 electrons.
कूलाम्ब का वैद्युत स्थितिकी का नियमCoulomb's law of electrostaticsThe force between two point charges is directly proportional to the product of their magnitudes and inversely proportional ta the square of the distance between them.
कूलाम्ब का चुम्बकत्व का नियमCoulomb's law of magnetismThe force between two magnetic poles is directly proportional to the strengths of the poles and inversely proportional to the square of their distance apart.
बल-युग्मcoupleTwo forces of equal magnitude acting in opposite directions in the same plane, but not along the same line.
शृंगcrestA region of upward displacement in a transverse wave.
क्रान्तिक कोणcritical angleThat limiting angle of incidence in the optically denser medium that results in an angle of refraction of 90o.
क्रान्तिक द्रब्यमानcritical massThe amount of a particular fissionable material required to make a fission reaction self-sustaining.
क्रान्तिक बिन्दुcritical pointThe upper limit of the temperature-pressure curve of a substance.
क्रान्तिक दाबcritical pressureThe pressure needed to liquefy a gas at its critical temperature.
क्रान्तिक तापcritical temperatureThe temperature to which a gas must be cooled before it can be liquefied by pressure.
क्रान्तिक वेगcritical velocityVelocity below which an object moving in a vertical circle will not describe a circular path.
क्यूरीcurieThe quantity of any radioactive nuclide that has a disintegration rate of 3.7 x 1O1O becquerels.
धारा संवेदनशीलताcurrent sensitivityCurrent per unit scale division of an electric meter. cut-off bias. The smallest negative grid voltage, for a given plate voltage, that causes a vacuum tube to cease to conduct.
देहली आवृतिcut-off frequencyA characteristic threshold frequency of incident light below which, for a given material, the photoelectric emission of electrons ceases.
देहली विभवcut-off potentialA negative potential on the collector of a photoelectric cell that reduces the photoelectric current to zero.
चक्रcycleA series of changes produced in sequence that recur periodically.
cyclotronA device for accelerating charged atomic particles by means of D-shaped electrodes.
मन्दनdampingThe reduction in amplitude of a wave due to the dissipation of wave energy.
क्षय नियतांकdecay constantThe ratio between the number of nuclei decaying per second and the total number of nuclei.
डेसीबेलdecibelA unit of sound intensity level. The smallest change of sound intensity that the normal human ear can detect.
declinationThe angle between magnetic north and the true north from any surface location; also called variation.
deesThe electrodes of a cyclotron.
घनत्वdensitySee mass density.
derived unitA unit of measure that consists of combinations of fundamental units .
dew pointThe temperature at which a given amount of water vapor will exert equilibrium vapor pressure.
diamagnetismThe property of a substance whereby it is feebly repelled by a strong magnet.
dichroismA property of certain crystalline substances in which one polarized component of incident light is absorbed and the other is transmitted.
dielectricAn electric insulator. A nonconducting medium.
dielectric constantThe ratio of the capacitance with a particular material separating the plates of a capacitor to the capacitance with a vacuum between the plates.
diffractionThe spreading of a wave disturbance into a region behind an obstruction .
diffraction angleThe angle that a diffracted wavefront forms with the grating plane.
diffraction gratingAn optical surface, either transmitting or reflecting, with several thousand equally spaced and parallel grooves ruled in it.
diffusion(1) The penetration of one type of particle into a mass of a second type of particle. (2)
विमीय विश्लेषणdimensional analysisThe performance of indicated mathematical operations in a problem with the measurement units alone.
डायोडdiodeA two-terminal device that will conduct electric current more easily in one direction than in the other.
दिष्ट धाराdirect currentAn essentially constant value current in which the movement of charge is in only one direction.
समानुपातdirect proportionThe relation between two quantities whose graph is a straight line.
dispersionThe process of separating polychromatic light into its component wavelengths.
विस्थापनdisplacement(1) A change of position in a particular direction. (2)
dissipative forcesForces for which the law of conservation of mechanical energy does not hold true; frictional forces.
आसवनdistillationThe evaporation of volatile materials from a liquid or solid mixture and their condensation in a separate vessel.
अपसारी लेंसdiverging lensA lens that is thicker at the edge than it is in the middle and bends incident parallel rays so that they appear to come from a common point.
domainA microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction.
donorA substance with five valence electrons per atom which when added to a semiconductor crystal provides free electrons in the lattice structure of the crystal.
डाप्लर प्रभावDoppler effectThe change observed in the frequency with which a wave from a given source reaches an observer when the source and the observer are in relative motion.
double refractionThe separation of a beam of unpolarized light into two refracted plane-polarized beams by certain crystals such as quartz and calcite.
drift tubesCharged cylinders used to accelerate charged subatomic particles in a linear accelerator.
ductilityThe property of a metal that enables it to be drawn through a die to form a wire.
भंवर धाराएंeddy currentsClosed loops of induced current set up in a piece of metal when there is relative motion between the metal and a magnetic field. The eddy currents are in such direction that the resulting magnetic forces oppose the relative motion.
एडिसन प्रभावEdison effectThe emission of electrons from a heated metal in a vacuum. effective value of current. The magnitude of an alternating current that in a given resistance produces heat at the same average rate as that magnitude of steady direct current.
दक्षताefficiencyThe ratio of the useful work output of a machine to total work input.
प्रत्यास्थ संघट्टelastic collisionA collision in which objects rebound from each other without a loss of kinetic energy.
प्रत्यास्थता सीमाelastic limitThe condition in which a substance is on the verge of becoming permanently deformed.
प्रत्यास्थ स्थितिज ऊर्जाelastic potential energyThe potential energy in a stretched or compressed elastic object.
प्रत्यास्थताelasticityThe ability of an object to return to its original size or shape when the external forces producing distortion are removed.
electric currentThe rate of flow of charge past a given point in an electric circuit.
वैद्युत क्षेत्रelectric fieldThe region in which a force acts on an electric charge brought into the region.
वैद्युत क्षेत्र की तीव्रताelectric field intensityThe force per unit positive charge at a given point in an electric field.
electric ground(1) A conductor connected with the earth to establish zero (ground)
electrificationThe process of charging a body by adding or removing electrons.
विद्युत रासायनिक सेलelectrochemical cellA cell in which chemical energy is converted to electric energy by a spontaneous electron transfer reaction.
विद्युत रासायनिक तुल्यelectrochemical equivalentThe mass of an element, in grams, deposited by one coulomb of electric charge.
विद्युताग्रelectrodeA conducting element in an electric cell, electronic tube, or semiconductor device.
वैद्युत अपघटनelectrolysisThe conduction of electricity through a solution of an electrolyte or through a fused ionic compound, together with the resulting chemical changes .
वैद्युत अपघट्यelectrolyteA substance whose solution conducts an electric current. electrolytic cell. A cell in which electric energy is converted to chemical energy by means of an electron-transfer reaction.
विद्युत चुम्बकीय प्रेरणelectromagnetic inductionThe process by which an emf is set up in a conducting circuit by a changing magnetic flux linked by the circuit.
electromagnetic interactionThe interaction that keeps electrons in orbit and forms bonds between atoms and molecules.
विद्युतचुम्बकीय तरंगेंelectromagnetic wavesTransverse waves having an electric component and a magnetic component, each being perpendicular to the other and both perpendicular to the direction of propagation.
विद्युत वाहक बलelectromotive forceSee emf.
इलेक्ट्रान्electronA negatively charged subatomic particle having a rest mass of 9.109534 x 10–31 kg and a charge of 1.6021892 x 10(1)9 c.
इलेक्ट्रान कक्षाelectron shellA region about the nucleus of an atom in which electrons move and which is made up of electron orbitals.
electron voltThe energy required to move an electron between two points that have a difference af potential of one volt.
इलेक्ट्रानिकीelectronicsThe branch of physics concerned with the emission, behavior, and effects of electrons.
विद्युतदर्शीelectroscopeA device used to observe the presence of an electrostatic charge.
मूल रंगelementary colorsThe six regions of color in the solar spectrum observed by the dispersion of sunlight: red, orange, yellow, green, blue, indigo, and violet.
elongation strainThe ratio of the increase in length to the unstretched length.
emfThe energy per unit charge supplied by a source of electric current.
emission spectrumA spectrum formed by the dispersion of light from an incandescent solid, liquid, and gas.
endothermicReferring to a process that absorbs energy.
ऊर्जाenergyThe capacity for doing work.
ऊर्जा स्तरenergy levelOne of a series of discrete energy values that characterize a physical system governed by quantum rules.
entropy(1) The internal energy of a system that cannot be converted to mechanical work. (2)
equilibrant forceThe force that produces equilibrium.
equilibriumThe state of a body in which there is no change in its motion.
equilibrium positionMidpoint of the path of an object describing simple harmonic motion.
equilibrium vapor pressureThe pressure exerted by vapor molecules in equilibrium with a liquid.
वाष्पनevaporationThe change of phase from a liquid to a gas or vapor.
अपवर्जन सिद्धान्तexclusion principleNo two electrons in an atom can have the same set of quantum numbers
exothermicReferring to a process that liberates energy.
external combustion engineA heat engine in which the fuel burns outside the cylinder or turbine chamber.
फैराडfaradThe unit of capacitance; one coulomb per volt.
फैराडेfaradayThe quantity of electricity (96,500 coulombs) required to deposit one chemical equivalent of an element.
फैराडे का प्रथम नियमFaraday's first lawThe mass of an element deposited during electrolysis is proportional to the quantity of charge that passes through the electrolytic cell.
फैराडे का द्वितीय नियमFaraday's second lawThe mass of an element deposited during electrolysis is proportional to the chemical equivalent of that element.
ferromagnetismThe property of a substance by which it is strongly attracted by a magnet.
Feynman diagramA diagram showing the production and exchange of particles during a subatomic interaction.
प्रकाश विद्युत उत्सर्जन का प्रथम नियमfirst law of photoelectric emissionThe rate of emission of photoelectrons is directly proportional to the intensity of the incident light.
उष्मागतिकी का प्रथम नियमfirst law of thermodynamicsWhen heat is converted to another form of energy, or when another form of energy is converted to heat, there is no loss of energy.
fissionThe splitting of a heavy nucleus into nuclei of intermediate mass.
flash tubeThe ionization tube that emits the light in a chemical laser.
Fleming valveThe first vacuum-tube diode.
fluorescenceThe emission of light during the absorption of radiation from another source.
fluxFlow.
f-numberThe ratio of the focal length of a lens to the effective aperture.
नाभीय दूरी/फोकस दूरीfocal lengthThe distance between the principal focus of a lens or mirror and its optical center or vertex.
नाभीय तलfocal planeThe plane perpendicular to the principal axis of a converging lens or mirror and containing the principal focus.
नाभिfocusA point at which light rays meet or from which rays of light appear to diverge.
बलforce(1) A physical quantity that can affect the motion of an object. (2)
गुरुत्व बलforce of gravitySee gravity.
forced vibrationVibration that is due to the application of a periodic force, and not to the natural vibrations of the system.
forward biasVoltage applied to a semiconductor P-N junction that increases the electron current across the junction.
fractional distillationThe process of separating the components of a liquid mixture by means of differences in their boiling points.
frame of referenceAny system for specifying the precise location of objects in space.
गलनांकfreezing pointThe temperature at which a liquid changes to a solid.
आवृतिfrequencyNumber of vibrations, oscillations, or cycles per unit time.
घर्षणfrictionA force that resists the relative motion of objects that are in contact with each other.
इंधन सेलfuel cellAn electrochemical cell in which the chemical energy of continuously supplied fuel is converted into electric energy.
fundamentalThe lowest frequency produced by a musical tone source. That harmonic component of a wave which has the lowest frequency.
मूल इकाईfundamental unitAny one of seven basic units of measure.
fusion(1) The change of phase from a solid to a liquid; melting. (2)
धारामापीgalvanometerAn instrument used to measure minute electric currents.
गामा किरणgamma rayHigh energy photon emitted from the nucleus of a radioactive atom.
Geiger tubeIon sensitive instrument used for the detection of subatomic particles.
गुरुत्व क्षेत्रgravitational fieldRegion of space in which each point is associated with a value of gravitational acceleration.
गुरुत्व बलgravitational forceThe mutual force of attraction between particles of matter.
gravitational interactionThe interaction between particles of matter that has no known distance limitations, but is the weakest interaction of all.
गुरुत्वीय स्थितिज ऊर्जाgravitational potential energyPotential energy acquired by an object when it is moved against gravity.
gravitonThe carrier for the gravitational interaction.
गुरुत्वgravityThe force of gravitation on an object on or near the surface of a celestial body.
gridAn element of an electronic tube. An electrode used to control the flow of electrons from the cathode to the plate.
grid biasThe grid-to-cathode voltage.
अर्ध कालhalf-lifeThe length of time during which, on the average, half of a large number of radioactive nuclides decay.
harmonicsThe fundamental and the tones whose frequencies are whole number multiples of the fundamental.
उष्माheatThermal energy in the process of being added to or removed from, a substance.
उष्मा धारिताheat capacityThe quantity of heat needed to raise the temperature of a body one degree.
heat engineAny device that converts heat energy into mechanical work.
गलन की उष्माheat of fusionThe heat required per unit mass to change a substance from solid to liquid at its melting point.
वाष्पन की उष्माheat of vaporizationThe heat required per unit mass to change a substance from liquid to vapor at its boiling point.
heat pumpA device that absorbs heat from a cool environment and gives it off to a region of higher temperature.
heat sinkA reservoir that absorbs heat without a significant increase in temperature.
हेनरीhenryThe unit of inductance; one henry of inductance is present in a circuit when a change in the current of 1 ampere per second induces an emf of 1 volt.
हुक का नियमHooke's lawBelow the elastic limit, strain is directly proportional to stress.
अति परवलयhyperbolaGraph of an inverse proportion.
hyperchargeA property of some baryons and leptons that is conserved in strong and electromagnetic interactions but not in weak interactions.
परिकल्पनाhypothesisA plausible solution to a problem.
हिमांकice pointThe melting point of ice when in equilibrium with water saturated with air at standard atmospheric pressure.
आदर्श गैसideal gasA theoretical gas consisting of infinitely small molecules that exert no forces on each other; also called perfect gas.
illuminationThe luminous flux per unit area of a surface.
प्रतिविम्बimageThe optical counterpart of an object formed by lenses or mirrors.
प्रतिबाधाimpedance(1) The ratio of applied wave-producing force to resulting displacement velocity of a wave-transmitting medium. (2)
impedance matchingA technique used to ensure maximum transfer of energy from the output of one circuit to the input of another.
आघातimpulseThe product of a force and the time interval during which it acts.
परावर्तन गुणांकindex of refractionThe ratio of the speed of light in a vacuum to its speed in a given matter medium.
प्रेरित चुम्बकत्वinduced magnetismMagnetism produced in a ferromagnetic substance by the influence of a magnetic field.
प्रेरकत्वinductanceThe Property of an electric circuit by which a varying current induces a back emf in that circuit or a neighboring circuit.
प्रेरणinductionThe process of charging one body by bringing it into the electric field of another charged body.
प्रेरणीय प्रतिबाधाinductive reactanceReactance in an a-c circuit containing inductance, which causes a lagging current.
अप्रत्यास्थ संघट्टinelastic collisionA collision in which the colliding objects stick together after impact.
जड़त्वinertiaThe property of matter that opposes any change in its state of motion.
inertial frame of referenceA nonaccelerating frame of reference in which Newton's first law holds true.
अवरक्त प्रकाशinfrared lightElectromagnetic waves longer than those of visible light and shorter than radio waves.
अवश्रव्य परासinfrasonic rangeVibrations in matter below 20 cycles/second.
ताक्षणिक धाराinstantaneous currentThe magnitude of a varying current at any instant of time.
ताक्षणिक वेगinstantaneous velocityShort displacement divided by elapsed time. Slope of the line that is tangent to a velocity graph at a given point.
instantaneous voltageThe magnitude of a varying voltage at any instant of time.
अचालकinsulatorA material through which an electric charge is not readily transferred.
तीव्रता स्तरintensity levelThe logarithm of the ratio of the intensity of a sound to the intensity of the threshold of hearing.
interactionAny change in the amount or quantum numbers of particles that are near each other.
interfaceA surface that forms the boundary between two phases or systems.
व्यतिकरणinterference(1) The superposing of one wave on another. (2)
internal combustion engineA heat engine in which the fuel burns inside the cylinder or turbine chamber.
आन्तरिक ऊर्जाinternal energyTotal potential and kinetic energy of the molecules and atomic particles of a substance.
intersecting storage ringAn accelerator in which particles collide as they move in opposite directions.
inverse photoelectric effectThe emission of photons of radiation from a material when bombarded with high speed electrons.
व्युत्क्रम अनुपातinverse proportionThe relation between two quantities whose product is a constant and whose graph is a hyperbola.
आयनionAn atom or a group of atoms having an electric charge.
ionization chamberA device used to detect the passage of charged rays or particles by their ionizing effect on a gas.
आयनन ऊर्जाionization energyThe energy required to remove an electron from an atom.
irregular reflectionScattering. Reflection in many different directions from an irregular surface.
समतापीय प्रक्रमisothermal processA thermal process that takes place at constant temperature.
समस्थानिकisotopesAtoms whose nuclei contain the same number of protons but different numbers of neutrons.
जूलjouleThe unit of work; the product of a force of one newton acting through a distance of one meter.
जूल का नियमJoule's lawThe heat developed in a conductor is directly proportional to the resistance of the conductor, the square of the current, and the time the current is maintained.
junction detectorA solid-state device based on the transistor principle that is used to detect the passage of charged particles.
केल्विन पैमानाKelvin scaleThe scale of temperature having a single fixed point, the temperature of the triple point of water, which is assigned the value 273.16 oK.
किलोग्रामkilogramA unit of mass in the metric system; one of the seven fundamental units.
किलोवाट घण्टाkilowatt hourA unit of electric energy equal to 3.6 x 106 w s.
गतिज ऊर्जाkinetic energyEnergy possessed by an object because of its motion.
गतिज सिद्धान्तkinetic theoryThe molecules of matter are continuously in motion and the collisions between molecules are perfectly elastic.
किरचाफ का प्रथम नियमKirchhoff's first lawThe algebraic sum of the currents at any circuit junction is equal to zero.
किरचाफ का द्वितीय नियमKirchhoff's second lawThe algebraic sum of all changes in potential occurring around any loop in a circuit equals zero.
लेजरlaserAn acronym for light amplification by stimulated emission of radiation.
नियमlawA statement that describes a natural phenomenon; a principle.
law of conservation of baryonsWhen a baryon decays or reacts with another particle, the number of baryons is the same on both sides of the equation.
ऊर्जा संरक्षण का नियमlaw of conservation of energyThe total quantity of energy in a closed system is constant.
law of conservation of hyperchargeHypercharge is conserved in strong and electromagnetic interactions, but not in weak interactions.
law of conservation of leptonsIn a reaction involving leptons, the arithmetic sum of the lepton numbers is the same on each side of the equation.
यांत्रिक ऊर्जा के संरक्षण का नियमlaw of conservation of mechanical energyThe sum of the potential and kinetic energies of an ideal energy system is constant.
संवेग संरक्षण का नियमlaw of conservation of momentumWhen no net external forces are acting on an object, the total vector momentum of the object remains constant.
law of entropyA natural process always takes place in such a direction as to increase the entropy of the universe.
उष्मा विनिमय का नियमlaw of heat exchangeIn any heat transfer system, the heat lost by hot materials equals the heat gained by cold materials .
लेंज का नियमLenz's lawAn induced current is in such a direction that its magnetic property opposes the change by which the current is induced.
leptonA subatomic particle with a small rest mass, e.g., the electron. line of flux. A line so drawn that a tangent to it at any point indicates the direction of the magnetic field.
बल रेखाline of forceA line so drawn that a tangent to it at any point indicates the direction of the electric field.
रेखीय स्पेक्ट्रमline spectrumA spectrum consisting of monochromatic slit images having wavelengths characteristic of the atoms present in the source.
रेखीय त्वरकlinear acceleratorA device for accelerating particles in a straight line through many stages of small potential difference.
द्रवीकरणliquefactionThe change to the liquid phase. The condensation of a gas to a liquid.
लीटरliterA special name for the cubic decimeter. Symbol: L.
अनुदैर्ध्य तरंगlongitudinal waveA wave in which the vibrations are parallel to the direction of propagation of the wave.
loopA midpoint of a vibrating segment of a standing wave.
loudnessThe sensation that depends principally on the intensity of sound waves reaching the ear.
lumenThe unit of luminous flux; the luminous flux on a unit surface all points of which are at unit distance from a point source of one candle:
luminousVisible because of the light emitted by its oscillating particles.
luminous fluxThe part of the total energy radiated per unit of time from a luminous source that is capable of producing the sensation of sight.
यंत्रmachineA device that multiplies force at the expense of distance or that multiplies distance at the expense of force.
चुम्बकीय क्षेत्रmagnetic fieldA region in which a magnetic force can be detected.
चुम्बकीय क्षेत्र की तीव्रताmagnetic field intensityThe force exerted by a magnetic field on a unit N pole situated in the field.
चुम्बकीय फ्लक्सmagnetic fluxLines of flux through a region of a magnetic field, considered collectively.
magnetic flux densityThe magnetic flux through a unit area normal to the magnetic field; also called magnetic induction.
चुम्बकीय बलmagnetic forceA force associated with motion of electric charges.
magnetosphereA region of the upper atmosphere in which the motion of charged particles is governed primarily by the magnetic field of the earth.
आवर्धनmagnificationThe ratio of the image distance to the object distance; the ratio of the image size to the object size.
malleabilityThe property of a metal that enables it to be hammered or rolled into sheets.
द्रब्यमानmassA measure of the quantity of matter; a fundamental physical quantity.
द्रब्य घनत्वmass densityMass per unit volume of a substance.
mass number(1) The sum of the number of protons and neutrons in the nucleus of an atom. (2)
mass spectrographInstrument used to determine the mass of ionized particles.
पदार्थmatterAnything that has the properties of mass and inertia.
द्रब्य तरंगेंmatter waveA property of matter that is directly proportional to Planck's constant and inversely proportional to mass and velocity.
उष्मा का यांत्रिक तुल्यांकmechanical equivalent of heatThe conversion factor that relates heat units to work units; 4.19 j/cal.
यांत्रिक तरंगmechanical waveA wave that originates in the displacement of a portion of an elastic medium from its normal position, causing it to oscillate about an equilibrium position.
माध्यमmediumAny region through which a wave disturbance propagates. Mechanical waves require a matter medium. Electromagnetic waves propagate through a vacuum and various matter media.
गलनांकmelting pointThe temperature at which a solid changes to a liquid.
meniscusThe crescent-shaped surface at the edge of a liquid column.
mesonA subatomic particle with a rest mass intermediate between that of a lepton and a baryon; the carrier of the strong interaction.
मीटरmeterA unit of length in the metric system equivalent to 1,650,763.73 wave-lengths of the orange-red light emitted by krypton-86. One of the seven fundamental units of measure.
मेट्रिक प्रणालीmetric systemA system of measurement that is based on decimal multiples and subdivisions.
मंदकmoderatorA material that slows down neutrons .
मोलmoleAmount of substance containing the Avogadro number of particles such as atoms, molecules, ions, electrons etc. It is 6.02 X 1023 particles.
अणुmoleculeThe smallest chemical species of a substance that is capable of stable independent existence.
संवेगmomentumThe product of the mass and velocity of a moving body.
एकवर्णीय प्रकाशmonochromatic lightLight composed of a single color.
अन्योन्य प्रेरणmutual inductanceThe ratio of the induced emf in one circuit to the rate of change of current in the coil of another circuit.
neutral weak currentA subatomic reaction in which leptons collide without change in the charges of the colliding particles .
न्यूरानneutronA neutral subatomic particle having a mass of 1.674943 x 10–27 kg.
न्यूटनnewtonThe unit of force; a derived unit having the dimensions kg m/s2. The force required to accelerate a one-kilogram mass at a rate of one meter per second each second.
न्यूटन का गति का प्रथम नियमNewton's first law of motionA body at rest or in uniform motion in a straight line will remain at rest or in the same uniform motion unless acted upon by an external force; also called the law of inertia.
न्यूटन का सार्वत्रिक गुरुत्व का नियमNewton's law of universal gravitationThe force of attraction between any two particles of matter in the universe is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers of mass.
न्यूटन का गति का द्वितीय नियमNewton's second law of motionThe acceleration of a body is directly proportional to the net force exerted on the body, is inversely proportional to the mass of the body, and has the same direction as the net force; also called the law of acceleration.
न्यूटन का गति का तृतीय नियमNewton's third law of motionIf one body exerts a force on a second body, then the second body exerts a force equal in magnitude and opposite in direction on the first body; also called the law of interaction.
nodeA point of no disturbance of a standing wave.
noiseSound produced by irregular vibrations in matter which is unpleasant to the listener.
noninertial frame of referenceAn accelerating frame of reference in which Newton's first law of motion does not hold true.
अभिलम्बnormalA line drawn perpendicular to a line or surface.
N-type germanium"Electron-rich" germanium consisting of equal numbers of free electrons and bound positive charges so that the net charge is zero.
नाभिकीय बंधन ऊर्जाnuclear binding forceThe force that acts within the small distances between nucleons .
नाभिकीय परिवर्तनnuclear changeA change in the identity of atomic nuclei.
nuclear mass defectThe arithmetic difference between the mass of a nucleus and the larger sum of its uncombined constituent particles.
नाभिकीय भट्ठी/रिएक्टरnuclear reactorA device in which the controlled fission of certain substances is used to produce new substances and energy.
nucleonA proton or neutron in the nucleus of an atom. (nucleus) The positively charged dense central part of an atom.
nuclideAn atom of a particular mass and of a particular element.
अष्टकoctaveThe interval between a given musical tone and one with double or half the frequency.
ओमohmThe unit of electric resistance; one volt per ampere.
ओम का नियमOhm's lawThe ratio of the emf applied to a closed circuit to the current in the circuit is a constant.
प्रकाशीय केन्द्रoptical centerThe point in a thin lens through which the secondary axes pass.
optical densityA property of a transparent material that is a measure of the speed of light through it.
कक्षकorbitalThe probability pattern of position of an electron about the nucleus of an atom.
order of magnitudeA numerical approximation to the nearest power of ten.
ordinateThe value corresponding to the vertical distance of a point on a graph from the X axis. The Y coordinate.
oscilloscopeA cathode-ray tube with associated electronic circuits that enable external voltages to deflect the electron beam of the cathode-ray tube simultaneously along both horizontal and vertical axes.
समान्तर परिपथparallel circuitAn electric circuit in which two or more components connected across two common points in the circuit so as to provide separate conducting paths for the current.
समान्तर चतुर्भुज विधिparallelogram methodThe graphic method of finding the resultant of two vectors that do not act along a straight line.
paramagnetismThe property of a substance by which it is feebly attracted by a strong magnet.
दोलकpendulumA body suspended so that it can swing back and forth about an axis.
penumbraThe partially illuminated part of a shadow.
कालperiod((1)) The time for one complete cycle, vibration, revolution, or oscillation. (2)
आवर्ती गतीperiodic motionMotion repeated in each of a succession of equal time intervals.
permeabilityThe property of a material by which it changes the flux density in a magnetic field from its value in air.
कलाphase(1) A condition of matter. (2)
phase angle(1) Of any periodic function, the angle obtained by multiplying the phase by 360 if the angle is to be expressed in degrees, or by 2pi if in radians. (2)
phasorA representation of the concepts of magnitude and direction in a reference plane; a rotating vector.
photoelasticPertaining to certain materials that become double refracting when strained.
प्रकाश वैद्युत प्रभावphotoelectric effectThe emission of electrons by a substance when illuminated by electromagnetic radiation of sufficiently short wavelength.
प्रकाश वैद्युत इलेक्ट्रानphotoelectronsElectrons emitted from a light-sensitive material when it is illuminated with light of sufficiently short wavelength.
प्रकाशमापीphotometerAn instrument comparing the intensity source with that of a standard source.
प्रकाशमितिphotometryThe quantitative measurement of visible radiation from light sources .
photonA quantum of light energy; the carrier of the electromagnetic interaction.
photovoltaic effectThe generation of a potential difference across a P-N junction as a consequence of the absorption of incident light of appropriate frequency.
भौतिक परिवर्तनphysical changeA change in which the composition and identifying properties of a substance remain unchanged. physical quantity. A measurable aspect of the universe, such as length.
भौतिकी/भौतिक विज्ञानphysicsThe science that deals with the relationships between matter and energy. The second half of life.
piezoelectric effectThe property of certain natural and synthetic crystals to develop a potential difference between opposite surfaces when subjected to a mechanical stress, and conversely.
pitchThe identification of a certain sound with a definite tone; depends on the frequency which the ear receives.
pivot pointThe point from which the lengths of all torque arms are measured.
प्लैंक नियतांकPlanck's constantA fundamental constant in nature that determines what values are allowed for physical quantities in quantum mechanics; h = 6.63 x 10-34 j s.
प्लाज्माplasmaA gas that is capable of conducting an electric current.
प्लेटplateThe anode of an electronic tube.
P-N junctionThe boundary between P and N-type materials in a semiconductor crystal.
ध्रुवित प्रकाशpolarized lightLight radiations in which the vibrations of all light waves present are confined to planes parallel to each other.
polarizing angleA particular angle of incidence at which polarization of reflected light is complete.
बहुवर्णी प्रकाशpolychromatic lightLight composed of several colors.
धन किरणेंpositive raysRays coming through holes in a cathode on the side opposite the anode in a discharge tube. Positively charged ions.
विभवान्तरpotential differenceThe work done per unit charge as a charge is moved between two points in an electric field.
स्थितिज ऊर्जाpotential energyEnergy that is the result of the position of an object. potential gradient. The change in potential per unit distance.
शक्ति/सामर्थ्यpowerThe time rate of doing work. power factor. The cosine of the phase angle between current and voltage in an a-c circuit.
precessionThe motion that results from the application of a torque that tends to displace the axis of rotation of a rotating object.
precisionThe agreement between the numerical values of two or more measurements made in the same way and expressed in terms of deviation; the reproducibility of measured data.
दाबpressureForce per unit area.
प्राथमिकprimaryA transformer winding that carries current and normally induces a current in one or more secondary windings.
प्राथमिक सेलprimary cellAn electrochemical cell in which the reacting materials must be replaced after a given amount of energy has been supplied to the external circuit.
primary colorsColors in terms of which all other colors may be described or from which all other colors may be evolved by mixtures.
primary pigmentsThe complements of the primary colors.
मुख्य अक्षprincipal axis(1) A line drawn through the center of curvature and the vertex of a curved mirror. (2)
मुख्य नाभिprincipal focusA point at which rays parallel to the principal axis converge or from which they diverge after reflection or refraction.
सिद्धान्तprincipleSee law.
principle of parityFor every process in nature there is a mirror-image process which is indistinguishable from the original process.
propagateTo travel through a material or space.
propagationThe act of propagating. The action of traveling through a material or space.
गुणpropertyA measurable aspect of matter, e.g., mass and inertia.
प्रोटानprotonA positively charged subatomic particle having a mass of 1.6726485 x 10–27 kg and a charge equal and opposite to that of the electron.
P-type germanium"Hole-rich" germanium consisting of equal numbers of free positive holes and bound negative charges so that the net charge is zero.
pulseA single nonrepeated disturbance.
qualityThe property of sound waves that depends on the number of harmonics and their prominence.
क्वांतमquantumAn elemental unit of energy; a photon of energy hf.
क्वांटम यांत्रिकीquantum mechanicsThe branch of physics that heals with the behavior of particles whose specific properties are given by quantum numbers.
क्वान्टम संख्याquantum numberOne of a set of notations used to characterize a discrete value that a quantized variable is allowed to assume.
क्वान्टम सिद्धान्तquantum theoryA unifying theory based on the concept of the subdivision of radiant energy into discrete quanta (photons) and applied to the studies of structure at the atomic and molecular levels. (quark)
quiescentA steady-state condition. The operating condition of an electronic circuit when no input signal is applied.
रेडियनradianA unit of angular measurement. The angle that, when placed with its vertex at the center of a circle, subtends on the circumference an arc equal in length to the radius of the circle. Approximately 57.3o.
रेडियो तरंगेंradio wavesAlso called Hertzian waves. Electromagnetic radiations produced by rapid reverses of current in a conductor.
रेडियोधर्मिताradioactivityThe spontaneous breakdown of an atomic nucleus with the emission of particles and rays.
रेडियो समस्थानिकradioisotopeAn isotope of an element that is radioactive.
विरलनrarefactionThe region of a longitudinal wave in which the vibrating particles are farther apart than their equilibrium distance .
किरणrayA single line of light from a luminous point. A line showing the direction of propagation of light.
प्रतिघातreactanceThe nonresistive opposition to current in an a-c circuit.
reaction motorA heat engine whose acceleration is produced by the thrust of exhaust gases.
वास्तविक प्रतिविम्बreal imageAn image formed by actual rays of light.
दिष्टकारीrectifierA device for changing alternating current to direct current.
rectilinear propagationTraveling in a straight line.
reflectanceThe ratio of the light reflected from a surface to the light falling on it, expressed in percentage.
परावर्तनreflectionThe return of a wave from the boundary of a medium.
अपवर्तनrefractionThe bending of a wave disturbance as it passes obliquely from one medium into another in which the disturbance has a different velocity.
regelationThe melting of a substance under pressure and the refreezing after the pressure is released.
regular reflectionReflection from a polished surface in which scattering effects are negligible.
सापेक्षिक विपथनrelative deviationPercentage average deviation of a set of measurements.
सापेक्षिक त्रुटिrelative errorPercentage absolute error of a set of measurements.
सापेक्षिक आर्द्रताrelative humidityThe ratio of the water vapor pressure in the atmosphere to the equilibrium vapor pressure at a given temperature.
relativistic massThe mass of an object in motion with respect to the observer.
residual magnetismMagnetism retained in a magnet after the magnetizing field has been removed.
प्रतिरोधresistanceThe ratio of the potential difference across a conductor to the magnitude of current in it.
प्रतिरोधकताresistivityA proportionality constant that relates the length and cross-sectional area of a given electric conductor to its resistance, at a given temperature.
resolution of forcesThe resolving of a single force into component forces acting in given directions on the same point.
अनुनादresonance(1) The inducing of vibrations of a natural rate by a vibrating source having the same frequency. (2)
rest massThe mass of an object not in motion.
परिणामीresultantA vector representing the sum of several vector components. resultant force. The single force that has the same effect as two or more forces applied simultaneously at the same point.
reverse biasVoltage applied to a semiconductor P-N junction that reduces the electron current across the junction.
rheostatA variable resistance.
वर्गमूल माध्य धाराroot-mean-square {rms} currentThe effective value of an alternating current; the square root of the mean of the instantaneous values squared.
घूर्णन गतिrotary motionMotion of a body about an internal axis.
rotational equilibriumThe state of a body in which the sum of all the clockwise torques in a given plane equals the sum of all the counterclockwise torques about a pivot point.
घूर्णीय जडत्वrotational inertiaThe property of a rotating object that resists changes in its angular velocity.
अदिश राशिscalar quantityA quantity that is completely specified by a magnitude.
scientific notationA positive number expressed in the form of M x 10n in which M is a number between 1 and 10 and n is an integral power of 10.
scintillation counterA device that counts the impacts of charged subatomic particles on a fluorescent screen by means of a photomultiplier tube.
सेकेण्डsecondA unit of time; equivalent to 9,192,631,770 vibrations of cesium(1)13. One of the seven fundamental units of measure.
प्रकाश वैद्युत उत्सर्जन का द्वितीय नियमsecond law of photoelectric emissionThe kinetic energy of photoelectrons is independent of the intensity of the incident light.
उष्मागतिकी का द्वितीय नियमsecond law of thermodynamicsIt is not possible for an engine to transfer heat from one body to another at a higher temperature unless work is done on the engine.
द्वितीयकsecondaryA transformer output winding in which the current is due to inductive coupling with another winding called the primary.
secondary axisAny line other than the principal axis drawn through the center of curvature of a mirror or the optical center of a lens.
द्वितियक उत्सर्जनsecondary emissionEmission of electrons as a result of the bombardment of an electrode by high-velocity electrons.
selectivityThe property of a tuned circuit that discriminates between signal voltages of different frequencies.
स्व-प्रेरणांकself-inductanceThe ratio of the induced emf across a coil to the rate of change of current in the coil.
श्रेणीक्रम परिपथseries circuitAn electric circuit in which the components are arranged to provide a single conducting path for current.
श्रेणीक्रम अनुनादseries resonanceA condition in which the impedance of a series circuit containing resistance, inductance, and capacitance is equal to the resistance of the circuit and the voltage across the circuit is in phase with the current.
shear strainThe ratio of the amount of deformation of the side of a body to the length of the side.
short circuitAn electric circuit through a negligible resistance that usually shunts a normal load and overloads the circuit.
significant figuresThose digits in an observed quantity (measurement) that are known with certainty plus the first digit that is uncertain.
सरल आवर्त गतिsimple harmonic motionMotion in which the acceleration is proportional to the displacement from an equilibrium position and is directed toward that position.
सौर स्पेक्ट्रमsolar spectrumThe band of colors produced when sunlight is dispersed by a prism.
परिनालिकाsolenoidA long helical wound coil of insulated wire.
solid state detectorA device used to detect the passage of charged subatomic particles by their crystal-distorting or ionizing effects on a nonconducting or nonconducting solid.
solidificationThe change of phase from a liquid to a solid.
sonometerA device, consisting of two or more wires or strings stretched over a sounding board, used for testing the frequency of strings and for showing how they vibrate.
ध्वनिsoundThe series of disturbances in matter to which the human ear is sensitive. Also similar disturbances in matter above and below the normal range of human hearing.
ध्वनि तीव्रताsound intensityThe rate at which sound energy flows through a unit area.
space chargeThe negative charge in the space between the cathode and plate of a vacuum tube.
spark chamberA device used to detect the passage of charged subatomic particles by the light flashes they trigger.
विशिष्ट गुरुत्वspecific gravityThe ratio of the mass density of a substance to that of water.
विशिष्ट उष्माspecific heatThe heat capacity of a material per unit mass.
spectroscopeOptical instrument used for the study of spectra.
चालspeedTime rate of motion.
गोलीय विपथनspherical aberrationThe failure of parallel rays to meet at a single point on a spherical surface after reflection or refraction.
spinthariscopeA device used to detect subatomic particles by the light flashes they produce on a zinc sulfide screen.
मानक दाबstandard pressureThe pressure exerted by 760 mm of mercury at O oC.
मानक तापstandard temperatureOoC, 273oK.
standing waveThe resultant of two wave trains of the same wavelength, frequency, and
आयामamplitudetraveling in opposite directions through the same medium .
स्थैतिक विद्युतstatic electricityElectricity at rest.
steam pointThe boiling point of water at standard atmospheric pressure.
स्टेरेडियनsteradianThe ratio of the intercepted surface area of a sphere to the square of the radius. A unit of solid angle.
भण्दारण सेलstorage cellAn electrochemical cell in which the reacting materials are regenerated by the use of a reverse current from an external source.
विकृतिstrainThe relative amount of distortion produced in a body under stress.
प्रतिवाधाstressThe distorting force per unit area.
strong nuclear interactionThe interaction that holds the particles of the nucleus together and is independent of charge.
उर्ध्वपातनsublimationThe change of a solid to a gaseous phase without passing through the liquid phase.
अतिचालकताsuperconductivityThe condition of zero resistivity below the transition temperature of a substance.
अतिशीतलनsupercoolingThe process of cooling a substance below its normal phase change point without a change of phase.
अध्यारोपणsuperpositionCombining the displacements of two or more waves vectorially to produce a resultant displacement.
पृष्ट तनावsurface tensionThe tendency of a liquid surface to contract; the measure of this tendency in newtons per meter.
sympathetic vibrationSee resonance (1).
synchrotronA particle accelerator in which the oscillating frequency varies.
प्रौद्योगिकीtechnologyThe application of science to human needs and goals.
तापtemperatureThe physical quantity that is proportional to the average kinetic energy of translation of particles in matter.
अस्थायी चुम्बकtemporary magnetA magnet produced by induction.
tensile strengthThe force required to break a rod or wire of unit cross-sectional area.
सिद्धान्तtheoryA plausible explanation of an observed event, supported experimentally and confirmed by experiments designed to test predictions based upon the explanation.
उष्मीय उर्जाthermal energyThe total potential and kinetic energy associated with the random motions of the particles of a material.
तापायनिक उत्सर्जनthermionic emissionThe liberation of electrons from the surface of a hot body.
तापयुग्मthermocoupleAn electric circuit composed of two dissimilar metals whose junctions are maintained at different temperatures .
उष्मागतिकीthermodynamicsStudy of quantitative relationships between heat and other forms of energy.
तापवैद्युत प्रभावthermoelectric effectThe production of an electron current in a closed circuit consisting of two dissimilar metals as a result of the emf developed when the two junctions are maintained at different temperatures.
thermonuclear reactionNuclear fusion.
प्रकाशवैद्युत उत्सर्जन का तृतीय नियमthird law of photoelectric emissionWithin the region of effective frequencies, the maximum kinetic energy of photoelectrons varies directly with the difference between the frequency of the incident light and the cut-off frequency.
thought experimentAn idealized experiment that cannot be performed under actual conditions.
threshold of hearingThe intensity of the faintest sound audible to the average human ear, 10(1)6 w/cm2 at 103 hz.
threshold of painFor audible frequencies of sound, an intensity level above which pain results in the average human ear. Rock concert.
toleranceDegree of precision obtainable with a measuring instrument.
बलाघूर्णtorqueProduct of a force and the effective length of its torque arm.
torque armThe perpendicular distance between the line of action of the torque producing force and the axis of rotation.
पूर्ण परावर्तनtotal reflectionThe reflection of light at the boundary of two transparent media when the angle of incidence exceeds the critical angle.
ट्रान्सफार्मरtransformerA device for changing an alternating voltage from one potential to another.
ट्रान्जिस्टरtransistorA semiconductor device used as a substitute for vacuum tubes in electronic applications.
transition temperatureA specific temperature at which the resistivity of some materials drops suddenly to zero.
translational equilibriumThe state of a body in which there are no unbalanced forces acting on it.
transuranium elementsElements with atomic number greater than 92.
अनुप्रस्थ तरंगtransverse waveA wave in which the vibrations are at right angles to the direction of propagation of the wave.
ट्रायोडtriodeVacuum tube consisting of a plate, grid, and cathode.
triple pointThe single condition of temperature and pressure at which the solid, liquid, and vapor phases of a substance can coexist in stable equilibrium.
troughA region of downward displacement in a transverse wave.
स्वरित्रtuning forkA metal two-prong fork that produces a sound of a definite pitch.
पराश्रव्य परासultrasonic rangeVibrations in matter above 20,000 vibrations/second.
पराबैगनी प्रकाशultraviolet lightElectromagnetic radiations of shorter wavelength than visible light but longer than X rays.
umbraThe part of a shadow from which all light rays are excluded.
अनिश्चितता का सिद्धान्तuncertainty principleIt is impossible to specify simultaneously both the position of an object and its momentum.
एकिकृत क्षेत्र सिद्धान्तunified field theoryThe principle that all forces in the universe are part of a single concept.
इकाई चुम्बकीय द्विध्रुवunit magnetic poleOne that repels an exactly similar pole placed one centimeter away with a force of one dyne.
भौतिक विज्ञान शब्दावली भौतिक विज्ञान शब्दावली Reviewed by rajyashikshasewa.blogspot.com on 6:56 PM Rating: 5

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