jee-main 2019 Q7

jee-main · India · session2_10apr_shift1 Not Maths
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 $135 ^ { \circ }$ and $0 ^ { \circ }$, respectively. If 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 $r _ { 2 }$, then the ratio $\frac { r _ { 1 } } { r _ { 2 } }$ is close to
(1) $\frac { 3 } { 5 }$
(2) $\frac { 2 } { 3 }$
(3) $\frac { 4 } { 5 }$
(4) $\frac { 2 } { 5 }$
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 $135 ^ { \circ }$ and $0 ^ { \circ }$, respectively. If 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 $r _ { 2 }$, then the ratio $\frac { r _ { 1 } } { r _ { 2 } }$ is close to\\
(1) $\frac { 3 } { 5 }$\\
(2) $\frac { 2 } { 3 }$\\
(3) $\frac { 4 } { 5 }$\\
(4) $\frac { 2 } { 5 }$