Question

an object placed at a distance of 25cm from a casts a real image at 40cm from its pole find the focal length
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Answer 1

Answer:

given

object distance u = -25cm

image distance v = -40cm ( as the image formed is real thus its on the left side of the mirror)

We know 1/f = 1/v + 1/u

=> 1/f = 1/-40 + 1/-25

=> 1/f = -0.065

f = 15.38D