∣hHg∣=∣hwater∣
ρ1r1g2S1cosθ1=ρ2r2g2S2cosθ2
Therefore, the ratio of the radii of the respective tubes is,
r2r1=ρ1ρ2×S2cosθ2S1cosθ1
r2r1=13.61×7.5×21
r2r1≈52
JEE Main 2019 — Physics Mechanics
The ratio of surface tensions of mercury and water is given to be 7.5, while the ratio of their densities is 13.6. Their contact angles, with glass, are close to 135∘ and 0∘, respectively. If it is observed that mercury gets depressed by an amount h in a capillary tube of radius r1, while water rises by the same amount h in a capillary tube of radius r2, then the ratio r2r1 is close to
Held on 10 Apr 2019 · Verified 6 Jul 2026.
53
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52
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