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Question 30899
JEE Physics · Hard

Elasticity, Thermal Expansion, Calorimetry and Heat Transfer: Thermal Expansion Advanced MCQ

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Thermal Expansion AdvancedHardQuestion 30899

Question

A steel scale is calibrated at 25°C (α = 1.2×10⁻⁵ /°C). At 5°C, a reading shows 1.00 m. True length is:
  1. A
    Slightly less than 1.00 m
    Correct
  2. B
    Exactly 1.00 m
  3. C
    Slightly more than 1.00 m
  4. D
    0.99976 m

Correct answer

Slightly less than 1.00 m

Explanation

Scale contracts at 5°C (below calibration). Each division is shorter, so scale overestimates. True length = reading × (1 − αΔT) < 1.00 m.

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