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InterviewSolution
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The image of an object placed on the principal axis of a concave mirror of focal length 12 cm is formed at a point which is 10cm more distance form the mirror than the object. The magnification of the image isA. 1.5B. 2C. 2.5D. 3 |
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Answer» Correct Answer - A `u=-x,v=-(10+x),f=-12` `(1)/(v)+(1)/(u)=(1)/(f)implies(1)/(-(10+x))+(1)/(-x)=(1)/(-12)` `(x+10+x)/((10+x)x)=(1)/(12)` `24x+120=x^2+10x` `x^2-14x-120=0` `(x-20)(x+6)=0` `x=20cm` `u=-20cm`, `v=-(10+20)=-30cm` `m=-(v)/(u)=-(-30)/(-20)=(3)/(2)=1.5` |
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