Question

The focal length of a convex lens is 10 cm. The magnifying powers when it is used as a magnifying glass to form the image at (i) near point and (ii) far point are :

• A. 2.5, 3.5
• B. 3.5, 4.5
• C. 4.5, 3.5
• D. 3.5, 2.5

Answer 1

The correct option is D 3.5, 2.5

For the near point, magnification, $m_1=1+\frac{D}{f}$

For the far point, $m_2=\frac{D}{f}$

Thus, putting $D=25$ and $f=10$

We get, $m_1=3.5$ and $m_2=2.5$