Q. The following observations were take for determining surface tension of water by capillary tube method. Diameter of capillary, $D = 1.25 \times 10^{- 2}$ m and rise of water in capillary. $h = 1.46 \times 10^{- 2}$m Taking $g = 9.80ms^{- 2}$ and using the relation $T = (rgh/2) \times 103Nm^{- 1}$, what is the possible error in surface tension$T$?
A) 2.4%
B) 15%
C) 1.6%
D) 0.15%
Explanation
Percentage error in $T = \frac{0.01}{1.26} \times 100 + \frac{0.01}{9.80} \times 100$ $+ \frac{0.01}{1.45} \times 100$ $= 0.8 + 0.1$+0.7=1.6
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.