Question

A lens of focal length 5 cm is being used by Debashree in the laboratory as a magnifying glass. Her least distance of distinct vision is 25 cm. What is the magnification obtained by using the glass?

Answer 1

The magnification obtained by Debashree using a lens of focal length 5 cm as a magnifying glass, with her least distance of distinct vision being 25 cm, is 6 times.

Step-by-step explanation:

The question asks about the magnification obtained when Debashree uses a lens with a focal length of 5 cm as a magnifying glass, given that her least distance of distinct vision is 25 cm. To find the magnification (M) when an object is viewed through a magnifying glass, we use the formula M = 1 + (D/f), where D is the least distance of distinct vision and f is the focal length of the lens.

Using Debashree's values:

1. D = 25 cm (least distance of distinct vision)
2. f = 5 cm (focal length of the lens)

Substitute these values into the formula:

M = 1 + (25 cm / 5 cm)

M = 1 + 5

M = 6

So the magnification obtained by Debashree using the magnifying glass is 6 times.