Exercises VIII — task. Science CBSE, Class 10.

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A concave lens of focal length \(15\ cm\) forms an image \(10\ cm\) from the lens. How far is the object placed from the lens? Draw the ray diagram.

Lens formula is,

\(\frac{1}{v}\ -\ \frac{1}{u}\ =\ \frac{1}{f}\)
\(\frac{1}{u}\ -\ \frac{1}{v}\ =\ \frac{1}{f}\)
\(\frac{1}{u}\ =\ \frac{1}{v}\ +\ \frac{1}{f}\)
\(\frac{1}{v}\ =\ \frac{1}{f}\ -\ \frac{1}{u}\)

Object distance (\(u\)) \(=\) \(cm\)

The object is placed,

behind the lens
in front of the lens

Important!

Note: Enter your answers with no decimal digits. Answer points are provided only for formulas and numerical answers. Draw the ray diagram in the white and compare it with the given answer.

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8. Exercises VIII

Exercise condition: