A thin disc of radius `R`, just touching the liquid surface forms one arm of a balance. The palte is balanced by some weight on the other side of the balance. How much extra weight should be added on the other side, so that the disc can just come cut of water ?

A thin disc of radius `R`, just touching the liquid surface forms one

1.	A thin disc of radius `R`, just touching the liquid surface forms one arm of a balance. The palte is balanced by some weight on the other side of the balance. How much extra weight should be added on the other side, so that the disc can just come cut of water ?
Answer» Surface tension force on the disc is `(T)(2piR)` For balance `(T)(2piR) = (Deltam)g rArr Deltam = ((T)(2piR))/(g)`

Discussion

No Comment Found

Related InterviewSolutions

Pressure inside two soap bubbles are `1.01` and `1.02` atmospheres. Ratio between their volumes isA. `2:1`B. `1:2`C. `8:1`D. `1:8`
Pressure inside two soap bubble are 1.02 and 1.03 atm . Then ratio of their volumes isA. `8 :27`B. `27:8`C. `(1.02)^(3) :(1.03)^(2)`D. `(1.03)^(3):(1.02)^(2)`
If the surface tension of water is ` 7.3 xx 10^(-2)` N/m then the excess pressure inside a spherical drop of water of radius ` 1 xx 10^(-3)` m formed will beA. `14.6 N//m^(2)`B. `146 N//m^(2)`C. `1460 N//m^(2)`D. ` 14600 N//m^(2)`
A capillary of internal radius `4 mm`, is dipped in water. To how much height, will the water rise in the capillary. (`T_(water) = 70 xx 10^(-3) N//m, g = 10 m//sec^(2), rho_(water) 10^(3) kg//m^(3)`, contact angle `theta rarr 0`)
Internal pressure inside a liquid drop of radius r and surface tension T isA. `(2T)/r-P_(0)`B. `(4T)/r + P_(0)`C. `P_(0)+(2T)/r`D. `T/(4r)-P_(0)`
Let `T_(1)` be surface tension between solid and air, `T_(2)` be the surface tension between solid and liquid and T be the surface tension between liquid and air. Then in equilibrium, for a drop of liquid on a clean glass plate, the correct relation is (`theta` is angle of contact) A. ` cos theta = T/(T_(1)+T_(2))`B. ` cos theta = T /(T_(1)-T_(2))`C. ` cos theta = (T_(1)+T_(2))/T`D. ` cos theta = (t_(1) - T_(2))/T`
Surface tension of a liquid is found to be influenced byA. It increases with the increase of temperatureB. Nature of the liquid in contactC. Presence of soap that increases itD. Its variation with the concentration of the liquid
Water does not wet an oily glass becauseA. cohesive force of oil `gt ` adhesive force between oil and glassB. cohesive force of oil `lt` cohesive force of waterC. oil repels waterD. cohesive force of water `gt` adhesive force between water and oil molecules
Mercury does not wet glass, wood or iron becauseA. Cohesive force is less than adhesive forceB. Cohesive force is greater than adhesive forceC. Angle of contact is less than `90^(@)C`D. Cohesive force is equal to adhesive force
Mercury does not wet wood . It indicates that its cohesive force isA. greater than its adhesive forceB. equal to its adhesive forceC. less than its adhesive forceD. none of these

A thin disc of radius `R`, just touching the liquid surface forms one arm of a balance. The palte is balanced by some weight on the other side of the balance. How much extra weight should be added on the other side, so that the disc can just come cut of water ?

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment