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Surface tension arises from the cohesive...

Surface tension arises from the cohesive force between the surface molecules. Interplay between cohesion and adhesion force make the surface inclined at acute or obtuse angle with the contacting solid surfaces. This causes a capillary rise (or fail) given as `h=(2Tcostheta)/(rhogr)`, where `theta=` angle of contact `T=` surface tension `rho=` density of the liquid, `g=` acceleration due to gravity and `r=` radius of the capillary tube.
In capillary rise:

A

heat is evolved

B

`U_(gr)` decrease

C

`U_("total")` increase

D

heat is absorbed

Text Solution

Verified by Experts

The correct Answer is:
A
Work done by surface tension is greater than that of gravity hence heat evolved.
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Knowledge Check

  • Surface tension arises from the cohesive force between the surface molecules. Interplay between cohesion and adhesion force make the surface inclined at acute or obtuse angle with the contacting solid surfaces. This causes a capillary rise (or fail) given as h=(2Tcostheta)/(rhogr) , where theta= angle of contact T= surface tension rho= density of the liquid, g= acceleration due to gravity and r= radius of the capillary tube. Q. In capillary action theta can be:

    A
    `0^(@)`
    B
    `90^(@)`
    C
    `90^(@)ltthetalt180^(@)`
    D
    all of these

  • Surface tension arises from the cohesive force between the surface molecules. Interplay between cohesion and adhesion force make the surface inclined at acute or obtuse angle with the contacting solid surfaces. This causes a capillary rise (or fail) given as h=(2Tcostheta)/(rhogr) , where theta= angle of contact T= surface tension rho= density of the liquid, g= acceleration due to gravity and r= radius of the capillary tube. Q. If the vessel accelerates up, capillary rise,

    A
    increases
    B
    decreases
    C
    remains the same
    D
    becomes zero

  • The potential energy of the liquid of surface tension T and density rho that rises into the capillary tube is

    A
    `pi^(2)T^(2)rho^(2)g`
    B
    `4piT^(2)rho^(2)g`
    C
    `(2piT^(2))/(rhog)`
    D
    `(piT^(2))/(rhog)`

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