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. It is observ…

Question

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. It is observed that mercury gets depressed by an amount h in a capillary tube of radius r_1, while water rises by the same amount h in a capillary tube of radius r_2. The ratio, ( r_1r_2 ), is then close to:

Accepted Answer

Correct answer: B. (b) JEE Main 2019 As we know that 2T cos rρg=h T_ HgT_ Water=7.5 _ Hg _W=13.6 \& cos _ Hg cos _W= cos135° cos0°= 1 2 R_ HgR_ Water= ( T_ HgT_W ) ( _W _ Hg ) ( cos _ Hg cos _W ) =7.5 113.6 1 2=0.4= 25

Solution

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