Question

if the focal length of a magnifying glass is 2.5cm it can magnify an object

Answer 1

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Here is ur answer

Given :- m=n/f+1

Here n is the near point which =25m

So , m= 25/2.5+1

10+1 =11
So it can magnify an object 11 times

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Answer 2

Magnifying class can magnify object by 11 times.

• Magnifying power of magnifying glass is given by

                          $m = \frac{LDDV}{f} + 1$

• LDDV is least distance of distinct vision is the minimum distance of an object from eye to have its clear image. It is 25 cm for normal human eye
• Focal length of magnifying glass = 2.5 cm
• Therefore, magnifying power of magnifying glass is

                           $m = \frac{25}{2.5} + 1$

                               $= \frac{1}{0.1} + 1$

                              $= 10 + 1\\= 11$