| A | B |
|---|
| Joule | The unit of work and energy, 1J = 1N-m |
| Kelvin's statement of second law of thermodynamics: | It is impossible that, at the end of a cycle of changes, heat has been extracted from a reservoir and an equal amount of work has been produced without producing some other effect |
| Kinetic energy | The energy possessed by a body due to its motion, it is equal to ½ mv2, where m is the mass and v is the speed of the body |
| Kepler's first law of planetary motion: | Each planet moves in an elliptical orbit, with the sun located at one of the foci |
| Kepler's second law of planetary motion: | The radius vector joining the planet to the sun covers equal areas in equal intervals of time. |
| Kepler's third law of planetary motion | The square of the period of a planet is directly proportional to the cube of the radius of the semi major axis of the orbit |
| Laser | A device that produces coherent light by stimulated emission of radiation |
| Latent heat of sublimation | The quantity of heat required to convert one unit mass of a substance from solid to gaseous state without any change in its temperature. |
| Law of Conservation of Energy | Energy can neither be created nor destroyed, but can be transformed from one form to another |
| Law of conservation of mass | Mass can neither be created nor destroyed in a chemical reaction. |
| Law of conservation of momentum: | In the absence of external forces, the total momentum of a group of interacting objects remains constant |
| Light-year: | The distance traveled by light through empty space in one year, it is equal to 9.46 x 1012 km. |
| Lenz's law: | The induced current always flows in such a direction that it opposes the cause producing it |
| Luminosity | The total amount of energy radiated each second from the surface of a source |
| Magnetic field | The region around a magnet where its magnetic force is experienced by other magnetic objects. |
| Mechanical energy: | The sum of energy possessed by a body due to its position, configuration and motion |
| Mole: | The amount of a substance that contains Avogadro's number of atoms, ions, molecules, or any other chemical unit; a mole is 6.02 x 1023 atoms, ions, or other chemical units. |
| Natural frequency | The frequency, with which a system oscillates in the absence of external forces, it depends on the size, composition, and shape of the object |
| Newton | The unit of force, equal to the force that will produce an acceleration of 1m/s2 in a body of mass1 kg. |
| Newton's first law of motion: | A body continues in a state of rest or of uniform motion in a straight line unless it is acted upon by an external (unbalanced) force. |
| Newton's law of gravitation: | The gravitational force of attraction acting between any two particles is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. The force of attraction acts along the line joining the two particles. |
| Newton's second law of motion: | The rate of change of momentum is directly proportional to the force applied |
| Newton's third law of motion: | To every action there is an equal and opposite reaction |
| Nuclear fission | The splitting a heavy nucleus into more stable, lighter nuclei with an accompanying release of energy |
| Nuclear fusion: | The combination of two lighter nuclei to form a heavier nucleus with an accompanying release of energy |
| Nucleons | A collective name for protons and neutrons |
| Ohm | Unit of resistance; = 1volt/ampere |
| Ohm's law | The current flowing through a conductor is directly proportional to the potential difference across the ends of the conductor. |
| Pascal | A unit of pressure, equal to the pressure resulting from a force of 1 Newton acting uniformly over an area of 1m2 |
| Pascal's law | The pressure exerted on a liquid is transmitted equally in all directions |
| Pauli Exclusion Principle | No two electrons in an atom can have the same four quantum numbers; thus, a maximum of two electrons can occupy a given orbital |
| Peltier effect | The evolution or absorption of heat at the junction of two dissimilar metals carrying current. |
| Photoelectric effect | The emission of electrons in some materials when light of suitable frequency falls on them. |
| Photons | A quanta of energy in light wave; the particle associated with light. |
| Planck's constant | The ratio of energy to frequency, equal to 6.63 x 10-34 joule-sec |
| Plasma | A highly ionized gas composed entirely of equal number of positive ions and electrons |
| Positron | An elementary particle having same mass as that of an electron but equal and positive charge |
| Projectile | An object which after being given an initial velocity is allowed to fall under the effect of gravity alone |
| Quantum mechanics | Model of the atom based on the wave nature of subatomic particles, the mechanics of electron waves; also called wave mechanics |
| Quark | One of the hypothetical basic particles, having charges whose magnitudes are one-third or two-third of the charge on an electron |
| Quantum numbers | Numbers that describe energy states of an electron |
| Radiation | The emission and propagation of waves transmitting energy through space or through some medium |
| Radiant energy | The form of energy that can travel through space; for example, visible light and other parts of the electromagnetic spectrum |
| Radioactive decay | The natural spontaneous disintegration or decomposition of a nucleus. |
| Refraction | The bending of light from its straight line path when it travels from one medium to another |
| Resonance | When the frequency of an external force matches the natural frequency of the body then the body oscillates with large amplitude. |
| Reverberation | The prolongation of sound at a given point after direct reception from the source has ceased, it is due to reflections from the boundary surfaces |
| Semiconductors | Elements whose electrical conductivity is intermediate between that of a conductor and an insulator |
| Saturated air | Air in which equilibrium exists between evaporation and condensation; the relative humidity is 100 percent |
| Solenoid | A cylindrical coil of wire that becomes electromagnetic when a current flows through it |
| Sonic boom | Sound waves that pile up into a shock wave when a source is traveling at or faster than the speed of sound. |
| Specific heat: | The amount of heat energy required to increase the temperature of one gram of a substance by 1 |
| Superconductors | Some materials in which, under certain conditions, the electrical resistance approaches zero |
| Surface tension | The property of a liquid due to which its surface behaves like a stretched membrane |
| Tesla | The S.I. unit of magnetic flux density, defined as the magnetic flux density of a magnetic flux of 1 Wb through an area of 1m2 |
| Thermal Capacity | The quantity of heat required to raise the temperature of the whole body by 1 |
| Trough | The point of maximum negative displacement on a transverse wave |
| Velocity: | Distance traveled by a body in a particular direction per unit time or the displacement of the body per unit time. It is a vector quantity |
| Van der Wall's force: | General term for weak attractive intermolecular forces |
| Volt | Unit of potential difference, equivalent to joule/coulomb |
| Voltage drop | The electric potential difference across a resistor or other part of a circuit that consumes power |
