12th physics short notes

 12th physics notes Defitions

(1) Uniform circular motion:-Perform uniform circular motion it moves circule or circular at constant linear speed or constant angular velocity.      (2) Centripetal force:-Uniform circular motion of particle, Centripetal force the forcr on particles at instant point radially inward produces .        (3) Centrifugal force:-reference frame of a particle performing circular motion,centrifugal force defined as a fictitious, radially outward force.                  4) Angle of banking: -angle of inclination of a banked road with the horizontal.         (5) Conical pendulum: -simple pendulum whose bob revolves in horizontal circle with constant speed that string describes surface right circular cone.                (6) Moment of inertia:-body a given axis of rotation is defined as sum of products the masses of particles of body.            (7)Radius of gyration:-Body rotating about axis is defined as distance between the axis rotation.        (8) Angular momentum of particle:-Particle as moment of linear momentum the particle.      (9)Gauge pressure:-Pressure exerted a fluid relative the local atmosphere pressure. Pg=p-P०.                 (10)Absolute pressure:-total pressure, measured relative to absolute zero the pressure scale-which perfect vacuum the sum gauge pressure.        (11)Range of molecular attraction or molecular range:-Maximum distance between two molecules up to intermolecular force.      (12)Sphere of influence:-Molecule is imaginary sphere drawn with molecule as centre.        (13) Surface tension:-Liquid is tangential force per unit length.                (14) Surface energy:-The extra energy of liquid surface an isothermal increase surface area.            (15)Angle of contact:-Liquid-solid pair as angle between surface of solid.                  (16) Velocity gradient a steady flow:-Steady flow of fluid past solid surface at velocity change with distance a limiting distance from surface.(17) Coefficient of viscosity:-Fluid is viscous drag per unit area acting on fluid layer per unit velocity.    (18)Root mean square speed of gas molecules:-Square root of arithmetic mean square of speed of molecules of gas given temp.               (19)Molar heat capacity of gas constant pressure:-Quntity of heat required to raise temp. of one mole of gas thr.one degree.        (20) Coefficient of transmission:-The ratio of quantity radiant energy transmitted by body.(21)Emissive power of a body:- the quantity of radiant energy emitted by body per unit time per unit surface area.        (22) Coefficient of emission of body:- ratio of emissive power of body to emissive power a blackbody.         (23) Internal energy:- system is as the sum of kinetic energies of atoms and molecules belonging the system.            (24) Efficiency of a heat engine:- ratio of work output to corresponding heat input, both work& heat expressed.     (25)Coefficient of performance of a refrigerator:-the ratio of heat absorbed by working substance.           (26)Periodic motion:-repeats itself at definite intervals of time.   #.Oscillatory motion:-body moves back and forth over the same path, straight or curved, between alternate extremes.           #. Linear simple harmonic motion :-linear periodic motion of a body in which the force on the body.    #.Period or periodic time of SHM:-time taken by particle performing simple harmonic motion complete one oscillation.          #.Frequency of SHM:-number of oscillations performed per unit time by a particle executing SHM.        #.Amplitude of SHM:-magnitude of maximum displacement a particle performing SHM from mean position.           #.Phase of SHM:-simple harmonic motion represents state of oscillation particle performing simple harmonic motion.      #.Ideal simple pendulum:-heavy point mass suspended rigid support by a weightless, inextensible and twistless string.        #.Seconds pendulum:-simple pendulum of period two seconds.        #.Angular SHM:-oscillatory motion of bodyto the angular displacement & oppositeof angular displacement.         #.Progressive wave OR Travelling wave:-wave motion is periodic or oscillatory disturbance a medium or in vacuum is propagated without damping.                   #.Longitudinal progressive wave:- vibration of individual particles of medium is linepropagation wave.              #. Transverse stationary wave:- opposite directions along same line superimpose, resultant wave produced.    #.Longitudinal stationary wave:- travelling in opposite directions along same line superimpose.    #.Free vibrations:- Vibrations of a body, free vibrate.    #.Forced vibrations:-body in response to an external periodic force.                 #. Beats:- periodic variation in loudness.     #.Period of beats:- time interval between successive maxima or minima sound at given place.    #. Beat frequency:- number of beats produced per unit time .        #. Wavefront:- surface all neighbouring points receive light waves from a source.           #.Wave normal:-wavefront a lined rawn perpendicular to wavefront the direction of propagation.                 #.The Brewster angle OR the polarizing angle:- interface angle incidence for ray.              #.Interference of light:-phenomenon in superposition two or more light waves produces.                 #.Diffraction of light:-phenomenon bending of light waves at edge.    #.Resolving power of a microscope:-reciprocal of least separation between two closely-spaced points.               #.Electric potential difference:-two points in electric field as work done per unit charge.        #. Electric potential:-work per unit charge that must be external agent against electric force to move acceleration.           #. The electronvolt:-electronvolt symbol, eV increase kinetic energy.#.Electric potential gradient:-electric potential distance० specified direction.  #.Electric polarization:-electric dipole moment per unit volume.    #.Capacitance of a capacitor:-ratio of charge either conductor to potential difference.         #.The SI unit of capacitance or capacity.The farad:- SI unit of capacitance is the farad.1farad=1coulomb/volt.     #.The ampere:-constant current which maintained two infinitely long straight parallel wires, one metre apart vacuum, would cause each conductor.    #.Magnetization:-material is net magnetic moment per unit volume ofmaterial.        #.Magnetic intensity:- magnetic induction in isotropic medium divided by the permeability of the medium.         #.Magnetic flux:-the total number of magnetic lines of force.    #.Electromagnetic induction:- production of emf in conductor or circuit due to motion.     #.Self induction:- emf change of current in the same coil.           #.Mutual induction:- induced emf in one coil due changing current.           #.Average value of an alternating emf or current:-M current is average value over half cycle.     #.Threshold frequency:-the characteristic minimum frequency of the incident radiation.          #.Threshold wavelength:-characteristic maximum wavelength of incident radiation which photoelectrons emitted from metal surface