Intext Questions XIII — task. Science CBSE, Class 10.

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எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்

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A convex lens forms a real and inverted image of a needle at a distance of \(50\ cm\) from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.

Lens formula is,

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

Power of lens is,

\(P\ =\ \frac{1}{f}\)
\(P\ =\ \frac{2}{f}\)
\(P\ =\ f\)
\(P\ =\ 2f\)

Distance of the object from lens (\(u\)) \(=\) \(cm\)

Focal length (\(f\)) \(=\) \(m\)

Power of lens (\(P\)) \(=\) \(D\)

Important!

Note: Enter your answers with two decimal digits.

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26. Intext Questions XIII

Exercise condition: