Question

An object is kept at 0.2 m from a convex lens of focal length 0.15 m. The position of the image is

Answer 1

Explanation:

$\blue{ \underline{ \bf{QUESTION : - }}}$

An object is kept at 0.2 m from a convex lens of focal length 0.15 m. The position of the image is?

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$\boxed{ \huge{ \bold{Given}}}$

Note:

$\boxed{ \underline{ \sf{I \: am \: Convert \: Value \: Meter \: (m) \: to \: Canti \: meter \: (cm)}}}$

• u= - 0.2 m = -20 cm

• f = 0.15 m = 15 cm

$\boxed{ \huge{ \bold{to \: find}}}$

• Position on the image

$\star{ \pink{ \underline{ \underline{Ｓｏｌｕｔｉｏｎ : - }}}}$

❒ By Using Lens Formula

$\boxed{ \boxed{ {\huge{ \bold{ \red{ \frac{1}{f} = \frac{1}{v} - \frac{1}{u}}}}}}}$

$\large{ \bold{ \frac{1}{15} = \frac{1}{v} - \frac{1}{( - 20)}}}$

$\large{ \bold{ \frac{1}{15} = \frac{1}{v} + \frac{1}{20}}}$

$\large{ \bold{ \frac{1}{15} - \frac{1}{20} = \frac{1}{v}}}$

$\large{ \bold{ \frac{4 - 3}{60} = \frac{1}{v}}}$

$\large{ \bold{ \frac{1}{60} = \frac{1}{v}}}$

$\large{ \bold{\purple{ \boxed{ \bold{v = 60 \: cm}}}}}$

${\therefore{ \green{ \sf{since ,\: the \: value \: of \: "v "\: is \: positive \: so \: image \: is \: real \: and \: inverted}}}}$

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MORE YOU KNOW ➥

• U = is the object of distance.

• V = image distance.

• f = Local length

$\boxed{ \sf{f = \frac{R}{2}}}$

• R = radius of curvature of the spherical mirror.

• For Lens U always taken as Negative.

• For focal length, f in lens is always taken as negative for concave and positive for convex.

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