Thermometer length affects scale spread for sensitivity Steps:

• Both thermometers have identical liquid volume and capillary diameter, so identical volume expansion per degree Celsius.
• The temperature range (span from lowest to highest measurable temperature) is the same, as they are nearly identical except for overall length.
• The longer thermometer distributes this expansion over a greater stem length, creating a more spread-out scale.
• This results in a larger distance per degree on the scale, increasing sensitivity (ease of reading small changes).

Why B is correct:

• Sensitivity is defined as scale length per unit temperature change; longer stem gives greater length per degree for fixed range, per the expansion formula h = (V₀ γ ΔT)/A (same V₀, γ, A).

Why the others are wrong:

• A: Ranges are not different; design assumes same span.
• C: Sensitivities are not the same; longer scale increases reading precision.
• D: Sensitivities differ due to scale length variation.

Final answer: B