Energy needed in the breaking of a drop of ra | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The energy required to break a large drop into smaller drops is equal to the work done against surface tension,which is stored as surface energy.S

Vedclass · Accepted Answer

$(4\pi r^2 n - 4\pi R^2)S$

Vedclass · Answer

(A) The energy required to break a large drop into smaller drops is equal to the work done against surface tension,which is stored as surface energy.Surface energy $U = S 	imes \Delta A$,where $S$ is the surface tension and $\Delta A$ is the change in surface area.Initial surface area of the drop of radius $R$ is $A_i = 4\pi R^2$.Final surface area of $n$ drops of radius $r$ is $A_f = n 	imes 4\pi r^2$.Change in surface area $\Delta A = A_f - A_i = 4\pi r^2 n - 4\pi R^2$.Therefore,the energy required is $U = (4\pi r^2 n - 4\pi R^2)S$.

Energy needed in the breaking of a drop of radius $R$ into $n$ drops of radius $r$ is given by : (With $S$ surface tension and $P$ atmospheric pressure)

Similar Questions

The work done in increasing the diameter of a soap bubble from $2 \ cm$ to $4 \ cm$ is (Surface tension of soap solution $= 3.5 \times 10^{-2} \ N/m$)

The surface tension of a soap solution is $0.03 \,N/m$. The work done in blowing to form a soap bubble of surface area $40 \,cm^2$ (in $J$) is:

$A$ mercury drop of radius $1\, cm$ is sprayed into $10^{6}$ drops of equal size. The energy expressed in joule is (surface tension of mercury is $460 \times 10^{-3}\, N/m$)

The amount of work done to break a big water drop of radius $R$ into $27$ small drops of equal radius is $10 \ J$. The work done required to break the same big drop into $64$ small drops of equal radius will be (in $J$)

The work done in blowing a soap bubble of radius $R$ is $W_1$ at room temperature. Now the soap solution is heated. From the heated solution another soap bubble of radius $2R$ is blown and the work done is $W_2$. Then:

Vedclass Test Series

Exam Paper Generator

Online Exam Module