AP EAPCET 04-Jul-2022 Shift 2 Paper

(c) For the first limb of the tube, height ascent by liquid
h1=‌

2T‌cos‌θ

rrρg

where, T= surface tension,
θ= angle of contact,
r1= radius of tube,
ρ= density of liquid and
g= gravitational acceleration.
For the second limb of the tube, height ascent by liquid,
h2‌=‌

2T‌cos‌θ

r2ρg

∴h1−h2‌=‌

2T‌cos‌θ

ρg

[‌

1

r1

−‌

1

r2

]

Given, T‌=0.03Nm−1,
r1‌=2‌mm=2×10−3m,
r2‌=4‌mm=4×10−3m,
θ‌=0∘,ρ=150‌kg‌m−3‌ and ‌g=10ms−2
h1−h2‌=‌

2×0.03×cos‌0∘

1500×10

[‌

1

2×10−3

−‌

1

4×10−3

]
‌=0.001m=1‌mm