Effect of thermal expansion on thermometer performance Steps:

• Sensitivity measures length change in the liquid column per unit temperature rise; larger expansion coefficient γ causes greater length change per °C.
• With same bulb volume V and capillary cross-section a, sensitivity dh/dT = (V γ)/a increases as γ increases.
• Range is maximum ΔT before liquid fills tube of length L; total expansion volume is aL.
• Max ΔT = (aL)/(V γ), so larger γ reduces max ΔT, giving smaller range.

Why A is correct:

• Larger γ boosts sensitivity via dh/dT ∝ γ but shrinks range via ΔT_max ∝ 1/γ, per volume expansion principles.

Why the others are wrong:

• B: Range decreases, not increases.
• C: Sensitivity increases, not stays same.
• D: Both sensitivity and range change.

Final answer: A