What is the magnification?

Question

When viewed through a magnifying glass, a stamp that is 1.2 cm wide appears upright and 5.6 cm wide. What is the magnification?

Answer 1

Hi Emma!

The answer to this question depends on the sign conventions you use for thin lenses.

The equation for magnification is: M = -di / do where M is the magnification, di is the distance the image is from the lens, and do is the distance the object is from the lens.

If the sign convention you use indicates that di should be negative when the image is formed on the object side of the lens (which it is in this case since it is a magnifying glass), then the magnification is M = -di / do

M = - (-5.6) / 1.2 = 4.67

Hope that is helpful!