Question

A student calibrated an eyepiece graticule using a stage micrometer. Each division of the stage micrometer was 0.01 mm. With a x10 magnification objective lens, 10 eyepiece graticule units matched 10 divisions on the stage micrometer. The same microscope was used with a x40, instead of a ×10, magnification objective lens to measure the diameter of an alveolus. The diameter of the alveolus was found to be 96 eyepiece graticule units. The eyepiece lens was not changed. What is the best estimate for the diameter of the alveolus? A 0.960 mm B 3.84 mm C 240 μm D 384 μm​

Answer 1

The best estimate for the diameter of the alveolus is approximately 38.4 μm.

To find the best estimate for the diameter of the alveolus, we can use the calibration information provided.

Calibration with x10 Magnification:

• Each eyepiece graticule unit matches 0.01 mm (given by the stage micrometer).
• 10 eyepiece graticule units match 10 divisions on the stage micrometer.

Calibration with x40 Magnification:

• The magnification is now x40 (4 times the original).
• The diameter of the alveolus is measured as 96 eyepiece graticule units.

Now, let's calculate the diameter using the x40 magnification:

`\[ \text{Diameter} = \text{Number of eyepiece graticule units} * \text{Calibration factor} \]`

`\[ \text{Diameter} = 96 \, \text{units} * \left(\frac{0.01 \, \text{mm}}{10 \, \text{units}}\right) * 4 \]`

`\[ \text{Diameter} = 0.0384 \, \text{mm} \]`

Now, convert the diameter to micrometers (1 mm = 1000 μm):

Diameter = 0.0384 mm x 1000 μm/mm

Diameter = 38.4 μm

Therefore, the best estimate for the diameter of the alveolus is approximately 38.4 μm.