2.2.5 Magnification Calculations

Key Formula:

$$Magnification=\frac{\text{Image Size}}{\text{Actual Size}}$$

• Rearranging this formula can help find missing values:
  • Image Size = Actual Size × Magnification
  • Actual Size = Image Size ÷ Magnification

Steps for Calculations:

1. Ensure Consistent Units:

• Convert measurements to the same unit (e.g., mm to μm, 1 mm = 1000 μm).
• Typical units include mm, μm, and nm.

2. Apply the Formula:

• Use the given data to calculate the required value (magnification, image size, or actual size).

3. Label Answers:

• Always include correct units in your answer.

Example:

• Question: The image of a cell measures 50 mm, and the magnification is x500. What is the actual size of the cell?
  • Formula:

$$Actual Size = \frac{\text{Image Size}}{\text{Magnification}}$$

• Calculation:

$$\text{Actual Size} = \frac{50 \, \text{mm}}{500} = 0.1 \, \text{mm}$$

• Convert to μm:

$$0.1 \, \text{mm} = 100 \, \text{μm}$$

• Answer: The actual size is 100 μm.