. An object of height 5 cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm

Use lens formula to determine the position, size and nature of the image if the  distance of the  object  from the lens  is 20 cm

Best Answer

Sol.  Height of the object, h1 = 5 cm

Focal length of the concave  lens, f = -10  cm Position of the object, v = ?      Size of the object, h2 = ? Object distance, u = -20  cm

According to lens formula:


Since h2 < h1 therefore image is diminished. The positive (+) sign for the magnification shows that  image  is erect  and  virtual.


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