Processing math: 100%


1)

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/s2 and the simplified relation  T=rhg2×103N/m.  The possible error in surface tension is closest to


A) 1.5%

B) 2.4%

C) 10%

D) 0.15%

Answer:

Option A

Explanation:

By ascent formula, we have surface tension.

                               T=rhg2×103N/m.

                                 =dhg4×103N/m.                 ( r=d2 )

                           TT=dd+hh  [ given g is constant]

   So ,percentage

               =TT×100=(dd+hh)×100

  =(0.01×1021.25×102+0.01×1021.45×102)×100=1.5%

TT×100= 1.5%