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Grade 11General Physics

a convex mirror is placed 20cm behind athin convex lens of 15cm focal length when a small object is placed at a distance og 20cm in front of the lens, the image formed at the same place calculata the focal length of the convex lens?

Profile image of Chaitanya Borah
16 Years agoGrade 11
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1 Answer

Profile image of Chetan Mandayam Nayakar
15 Years ago

for lens, (1/20)+(1/v) = 1/15, therefore v=60cm

for mirror, (1/U)+(1/V)=1/f

U= -25cm and V= 35cm

therefore, f= -87.5cm