Question

1. You are viewing a bug under a magnifying glass. If the focal length of the glass is 5cm and thebug is placed 2cm from the glass, how many times bigger does the bug appears to be?

Answer 1

Given:

The focal length of the magnifying glass is f = 5 cm

The object distance is u = -2 cm

Required:

The magnification of the bug.

Step-by-step explanation:

First, we need to find the image distance using the lens formula

The image distance will be

`\begin{gathered} (1)/(v)-(1)/(u)=(1)/(f) \\ (1)/(v)=(1)/(f)+(1)/(u) \\ =(1)/(5)+(1)/(-2) \\ v=-(10)/(3)\text{ cm} \\ =-3.33\text{ cm} \end{gathered}`

The magnification can be calculated as

`\begin{gathered} m\text{ = }(v)/(u) \\ =(-10)/(3)*(1)/(-2) \\ =\text{ 1.67 } \end{gathered}`

Thus, the magnification of the bug is 1.67.

Final Answer: The bug appears 1.67 times bigger.