Focal Length and Power of a Magnifying Glass Calculation

a) What is the focal length of the magnifying glass?

Given that the magnification is 3 and the distance is 4.5 cm, what is the focal length of the magnifying glass?

b) How to calculate the power of the magnifier in diopters?

What is the formula to calculate the power of the magnifier and how can we find the power in diopters?

Answer:

The focal length of the magnifying glass is 2.25 cm and the power of the magnifier is 0.44 diopters.

To find the focal length of the magnifying glass, we can use the formula: magnification = (1 + (d/f)) where m is the magnification, d is the distance from the object to the lens, and f is the focal length. Given that the magnification is 3 and the distance is 4.5 cm, we can rearrange the equation and solve for f: f = d / (m - 1) = 4.5 / (3 - 1) = 2.25 cm Therefore, the focal length of the magnifying glass is 2.25 cm. The power of a lens is given by the formula: Power (P) = 1 / f Substitute the focal length (2.25 cm) into the formula: P = 1 / 2.25 = 0.44 diopters Hence, the power of the magnifier is 0.44 diopters.