A5 cm object is 18.0 cm from a convex lens, which has a focal length of 10.0 cm. What is the distance of the image from the lens? Roun

Question

A5 cm object is 18.0 cm from a convex lens, which has a focal length of 10.0 cm.
What is the distance of the image from the lens? Round your answer to three significant figures.
cm
What is the height of the image? Round your answer to three significant figures.
cm
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Tryphena 6 months 2021-07-19T07:25:40+00:00 1 Answers 21 views 0

Answers ( )

    0
    2021-07-19T07:27:24+00:00

    Explanation:

    We have,

    Height of object is 5 cm

    Object distance from a convex lens is 18 cm

    Focal length of convex lens is 10 cm

    i.e. h = 5 cm

    u = -18 cm

    f = +10 cm

    Let v is distance of the image from the lens. Using lens formula :

    \dfrac{1}{f}=\dfrac{1}{v}-\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{f}+\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{10}+\dfrac{1}{(-18)}\\\\v=22.5\ cm

    The magnification of lens is :

    m=\dfrac{v}{u}=\dfrac{h'}{h}, h’ is height of the image

    \dfrac{v}{u}=\dfrac{h'}{h}\\\\h'=\dfrac{vh}{u}\\\\h'=\dfrac{22.5\times 4}{(-18)}\\\\h'=-5\ cm

    h’ = -5.00 cm (in three significant figures)

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