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A point object is kept at a distance of 2 m from a parabolic reflecting surface y^(2) = 2x . An equiconvex lens is kept at a distance of 1.80 m from the parabolic surface. The focal length of the lens is 20 cm . Find the position from origin of the image in cm, after reflection from the surface. |
Answer» SOLUTION :_S01_032_S01.png) Comparing with `y^(2) = 4"ax" implies a = 0.5` `PC` is a normal so `"tan"(pi-theta) = (-1)/((dy//dx)_(x_(1)y_(1))) = -y_(1) implies ` final position of image = `0.5"m" = 50 "CM"` But `"tan"2THETA = (y_(1)-0)/(x_(2)-x_(1))` & `"tan"2theta = (2"tan"theta)/(1-tan^(2)theta) implies (xy_(1))/(x_(2) - x_(1)) = (2(y_(1)))/(1-y_(1)^(2))x_(2) = (1)/(2)"m"` |
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