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BS.E. (Dethi, , , , ». such that CB portion of the pencil is immersed in water as s g, ne pencil bend away from the normal as they go from water to air. The refract, Thus, the immersed portion of pencil in water appears as CB’. +, surface. Moreover, the immersed portion of the pencil in water also appears to, ngth of the peneil., , , , , , FORMULAE USED: On=ae (anae, , c=3~x 108 ms., UNITS :_ nis dimensionless has no unit. i and rare measured in degrees, v in ms, the refractive index of a material if angle of incidence of ray of light is 45° and angle of refraction ix, , 1, , , , (CBSE. 2, rion. Here, i = 45°, r = 30° si, a ‘ 0., sini _ sin45? _, Using n= aan, we have n “Sin30° _0-5000, , or n = 1-414, : Thus, refractive index of the material is 1-414. oa kn, | 2. The speed of light in air is 3 * 108 ms and the speed of light in waters ~\, , 8 1, Solution. Here, c=3* 10° ms, ve 2:26 x 10” ms, , mm, , , , 2008, 2011, , Rays of light, , , , O11, Similar 2016, , (C.B.S.E. 2011, 2012)