Converting mm to μm for eyepiece graticule calibration

Steps:

• Identify stage micrometer division size: 0.1 mm.
• Select appropriate unit for microscopy calibration: micrometers (μm), where 1 mm = 1000 μm.
• Apply conversion by multiplying: 0.1 mm × 1000 = 100 μm per stage division.
• Use this value to determine eyepiece unit size by comparing divisions in the diagram.

Why C is correct:

• C multiplies 0.1 mm by 1000 to convert to μm using the standard metric prefix factor (milli- to micro-).

Why the others are wrong:

• A: Divides instead of multiplies and keeps mm units, yielding incorrect 0.0001 mm.
• B: Divides by 1000 for μm, producing erroneously small 0.0001 μm.
• D: Uses incorrect factor (10000) and nm units; 0.1 mm actually equals 100000 nm.

Final answer: C