Q3 of 27 Page 132

The focal length of a converging lens is 20 cm. An object is 60 cm from the lens. Where will the image be formed and what kind of image is it? (AS1)

Focal length (F) = 20cm

Object distance (u) = -60cm


Image distance (v) = ?


Using Lens formula:







v = 60/2 = 30cm


As the object is beyond the centre of curvature (2F = 40cm), then the image will be formed between focus & centre of curvature. The image will be real, diminished, inverted and 30 cm away from the lens.



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