CHAPTER01 Class XII ELECTRIC CHARGES AND FIELDS P2 CHAPTER ELECTROSTATIC POTENTIAL 02 AND CAPACITANCE Class XII P4 . CHAPTER 07 GRAVITATION Class XI P14 . then P = dioptre. It is denoted by ic. 1) f w The SI unit of power of lens is SIMPLE MICROSCOPE COMPOUND MICROSCOPE REFRACTIVE INDEX dioptre (D). P is negative. w Light must travel from denser to rarer. f through an angle q. f f f COMMON DEFECTS OF EYES « CORRECTING LENSES w Myopia (short-sightedness)« Concave lens For final image is formed at infinity. refraction is 90°. ASTRONOMICAL TELESCOPE For final image is formed at D (least distance).mrarer ö æ 1 1 ö back into the same medium. object and of the same size as the 1 2 object then m is positive.CHAPTER 08 RELATION BETWEEN m AND iC RAY OPTICS AND OPTICAL INSTRUMENTS DISPERSION OF LIGHT The phenomenon of splitting of white The angle of incidence in the optically light into its constituent colours on denser medium for which the angle of passing through a prism. Class XII Deviation of red light(dR) t P ible ligh Deviation of R violet light (dV) w If i < ic. f where.t. Magnifying power Magnifying power. image A = angle of prism REFLECTION BY SPHERICAL MIRRORS TOTAL INTERNAL REFLECTION distance (v) and refractive index (m) REFLECTION FROM (Holds for or d = (m – 1)A (Prism of small angle) The phenomenon in which a ray of light any curved Mirror formula.t. P is positive. the normal to the interface at the point of incidence and the refracted w Fiber optics communication w Medical endoscopy reflection r..R ÷ø Mean deviation. = If the image is upright or erect with respect to the mirror is virtual. f çè mrarer ÷ø çè R . for the two media is totally reflected w The image formed by a plane 1 æ mdenser . m = For final image formed at infinity f at infinity b –f f m= =a f f COMBINATION OF LENSES f Newtonian reflecting telescope w Power: P = P1 + P2 – dP1P2 w In normal adjustment. OPTICAL ray all lie in the same plane.. at infinity m= f (in cm) D Angle subtended by the object For final image formed at infinity. image formed at infinity TERRESTRIAL TELESCOPE (d = small separation between the lense) m = – fo / fe REFLECTING TELESCOPE w For d = 0 (lenses in contact) f f Eyepiece lens For final image is formed at D. f Objective mirror A terrestrial telescope When the final image is formed at D. the normal and the reflected INSTRUMENTS w Snell’s law: w w Mirage ray lie in the same plane. Vis A O Y w If i = ic. w Angle of incidence is greater than the plane mirror is rotated critical angle. m = mo × me w For a convex lens.r. For final image formed at D (least distance) w For a concave lens. then refraction takes place. then total internal reflection E Thin lens formula : N H takes place. And m is negative if the TIR conditions object. w Totally reflecting glass prisms Power of lens : (1m2 = refractive index of medium 2 w. m = incidence greater than the critical angle mirror is laterally inverted. Magnifying power Angle subtended by the image at D b w For final image is formed at D (least distance). erect w. m f Light from object at Upright image m = o 1+ e fe D ( ( Telescope tube Light w Hypermetropia (long-sightedness) « Convex lens infinity Inverted image When the final image is formed at infinity Diagonal mirror Distance between objective and eyepiece w Presbyopia « Bifocal lens f d = fo + 4f + fe Objective lens Erecting lenses Eyepiece m= w Astigmatism « Cylindrical lens f f P16 . THIN SPHERICAL LENS i r r e Angular B I Relation between m and dm F 1q 2G spread V Screen w If i > ic.e. for the lens placed in air image is inverted with respect to the object. w Periscope (Using prism) Ði = Ðr Sparkling of diamond POWER OF LENSES w Incident ray.r.. PLANE SURFACE Angular dispersion = dV – dR = (mV – mR)A f travelling from an optically denser into spherical surface) an optically rarer medium at an angle of w The image formed by a plane Magnification. then grazing emergence takes (i– r1) (e– r 2) REFRACTION THROUGH PRISM N1 d N2 G place. w Deviation suffered by a light ray REFLECTION OF LIGHT RAY OPTICS Laws of refraction : APPLICATIONS OF TIR Laws of reflection: incident at an angle i is given by d = (180° – 2i) w The angle of incidence i equals the angle of & w The incident ray. b vo æ Dö L æ Dö w When focal length (f) of lens is in =a = m= = çè1 + f ÷ø = f çè1 + f ÷ø m= Real and apparent depth 100 Angle subtended by the object f Angle subtended by the image at D a uo e 0 e cm. w If keeping the incident ray fixed. 2q in that direction. m Magnifying power w Power: P = P1 + P2 + P3 + . Lens maker’s formula Dispersive power. the reflected ray turns through double the REFRACTION OF LIGHT angle i. Q R REFRACTION BY SPHERICAL SURFACE dm = angle of minimum Magnification: deviation Relation between object distance (u). CHAPTER 09 WAVE OPTICS Class XII P18 .