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 r1, while water rises by the same amount h in a capillary tube of radius r2. The ratio,\(\left( {\frac{{{r_1}}}{{{r_2}}}} \right)\) , is then close to:

The ratio of surface tensions of mercury and water is given to be 7 :

1.	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 r1, while water rises by the same amount h in a capillary tube of radius r2. The ratio,\(\left( {\frac{{{r_1}}}{{{r_2}}}} \right)\) , is then close to:
A.	4/5
B.	2/5
C.	3/5
D.	2/3
Answer» C. 3/5