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The following observations were taken for determining surface tension T of water by capillary method:
Diameter of capillary, D=1.25×10⁻² m
rise of water, h=1.45×10⁻² m
Using g=9.80 m s⁻² and the simplified relation, T=(rhg)/2×10³ N m⁻¹, the possible error in surface tension is closest to

Asked in JEE Main 2017 · Surface tension, viscosity and calorimetry

• (1) 0.15%
• (2) 1.5%
• (3) 2.4%
• (4) 10%

Step-by-step solution

Why the other options are wrong

• (1) comes from the right sum with the decimal point moved one place, which is what reading Δ D as 0.001×10⁻² does
• (3) comes from adding the two terms and then doubling, as if the radius entered squared
• (4) comes from taking the last digit of each reading as a whole unit of the leading digit

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