A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If of work is done in blowing it further to make its diameter 14 cm, then the value of is _______. [2026]

Question

A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If $(15000 - x) μ J$ of work is done in blowing it further to make its diameter 14 cm, then the value of $x$ is _______. $(π = 22 / 7)$ [2026]

Smart Achievers · Accepted Answer

(11304)

$W = Δ u$

$= S \times (8 π r_{2}^{2} - 8 π r_{1}^{2})$

$= 0.04 \times 2 \times \frac{22}{7} (147) \times 10^{- 4}$

$W = 3696 \times 10^{- 6} J$

$3696 = 15000 - x$

$x = 11304 μ J$

Solution

Q.
A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If $(15000 - x) μ J$ of work is done in blowing it further to make its diameter 14 cm, then the value of $x$ is _______. $(π = 22 / 7)$ [2026]

Ans.
(11304)

$W = Δ u$

$= S \times (8 π r_{2}^{2} - 8 π r_{1}^{2})$

$= 0.04 \times 2 \times \frac{22}{7} (147) \times 10^{- 4}$

$W = 3696 \times 10^{- 6} J$

$3696 = 15000 - x$

$x = 11304 μ J$

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Solution

Q. A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If (15000-x) μJ of work is done in blowing it further to make its diameter 14 cm, then the value of x is _______. (π=22/7) [2026]

Ans. (11304) W=Δu =S×(8πr22-8πr12) =0.04×2×227(147)×10-4 W=3696×10-6 J 3696=15000-x x=11304 μJ

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Q.
A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If $(15000 - x) μ J$ of work is done in blowing it further to make its diameter 14 cm, then the value of $x$ is _______. $(π = 22 / 7)$ [2026]

Ans.
(11304)

$W = Δ u$

$= S \times (8 π r_{2}^{2} - 8 π r_{1}^{2})$

$= 0.04 \times 2 \times \frac{22}{7} (147) \times 10^{- 4}$

$W = 3696 \times 10^{- 6} J$

$3696 = 15000 - x$

$x = 11304 μ J$