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9.2 , surface tension — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysics9.2 , surface tension1 Mark
MCQ
A soap film is formed on a circular frame. A loop of thread is lying on film. If the film inside the loop is broken, then tension in the thread will be : ($R =$ radius of loop, $T =$ surface tension of liquid)
  • A
    $2\pi RT$
  • B
    $\pi RT$
  • ✓
    $RT$
  • D
    $\pi {R^2}T$
✓

Answer

Correct option: C.
$RT$
c
$\Rightarrow 2 \mathrm{T}^{\prime} \sin \theta=\mathrm{T} \delta \ell$

$2 \mathrm{T}^{\prime} \theta=\mathrm{T}(2 \theta . \mathrm{R})$

Tension $\left.\mathrm{T}^{\prime}=\mathrm{RT}\right]$

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