A soap bubble of radius r is blown up to form | vedclass

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

Question

(D) soap bubble has two surfaces (inner and outer). Initially, the surface area of the soap bubble is $A_1 = 4 \pi r^2$. Since it has two surfaces, th

Vedclass · Accepted Answer

$24$

Vedclass · Answer

(D) soap bubble has two surfaces (inner and outer). Initially, the surface area of the soap bubble is $A_1 = 4 \pi r^2$. Since it has two surfaces, the effective initial area is $S_1 = 2 	imes (4 \pi r^2) = 8 \pi r^2$. Under isothermal conditions, the radius becomes $2r$. The new surface area is $A_2 = 4 \pi (2r)^2 = 16 \pi r^2$. The effective final area is $S_2 = 2 	imes (16 \pi r^2) = 32 \pi r^2$. The increase in surface area is $\Delta S = S_2 - S_1 = 32 \pi r^2 - 8 \pi r^2 = 24 \pi r^2$. The energy spent $(W)$ is given by $W = T 	imes \Delta S$. Therefore, $W = T 	imes 24 \pi r^2 = 24 \pi T r^2$.

$A$ soap bubble of radius $r$ is blown up to form a bubble of radius $2r$ under isothermal conditions. If $T$ is the surface tension of the soap solution, what is the energy spent in blowing the bubble (in $\pi T r^2$)?

Similar Questions

If the surface tension of a soap solution is $3 \times 10^{-2} \,N/m$, then the work done in forming a soap film of $20 \,cm \times 5 \,cm$ will be

If $T$ is the surface tension of a soap solution, then the amount of work done in increasing the diameter of a soap bubble from $D$ to $2D$ is: (in $\pi D^2 T$)

In $S.I.$ system,the total energy of the free surface of a liquid drop is $2 \pi$ times the surface tension of the liquid. The diameter of the drop is . . . . . . . (in $m$)

$A$ liquid drop of diameter $D$ splits into $3375$ small identical drops. If $S$ is the surface tension of the liquid,then the change in the surface energy in the process is

Energy required to form a soap bubble of diameter $20 \, cm$ will be (Surface tension for soap solution is $30 \, dynes/cm$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module