Question

table 3.1.
objective lens | total magnification | field diameter (in mm) | field diameter (in μm)
--- | --- | --- | ---
scanning power | 40 | 4.7 |
low power | 100 | 1.9 |
high power | 400 | 0.475 |

Explanation:

Step1: Convert mm to μm (scanning)

Recall $1\ \text{mm} = 1000\ \mu\text{m}$.
$4.7\ \text{mm} \times 1000 = 4700\ \mu\text{m}$

Step2: Convert mm to μm (low power)

$1.9\ \text{mm} \times 1000 = 1900\ \mu\text{m}$

Step3: Convert mm to μm (high power)

$0.475\ \text{mm} \times 1000 = 475\ \mu\text{m}$

Answer:

Objective Lens	Total Magnification	Field diameter (in mm)	Field diameter (in μm)
Low power	100	1.9	1900
High power	400	0.475	475