2. Solved Papers
  3. JCECE Engineering

JCECE Engineering JCECE Engineering Solved Paper-2008

  • question_answer
    A frame made of metallic wire enclosing a surface area \[A\] is covered with a soap film. If the area of the frame of metallic wire is reduced by\[50%\], the energy of the Soap film will be changed by

    A) \[100%\]                             

    B) \[75%\]

    C)  \[50%\]                                              

    D)  \[25%\]

    Correct Answer: C

    Solution :

    Surface energy = surface tension\[\times \]surface area                         \[E=T\times 2A\] New surface energy,                       \[{{E}_{1}}=T\times 2\left( \frac{A}{2} \right)=T\times A\] \[%\]decrease in surface energy                           \[=\frac{E-{{E}_{1}}}{E}\times 100\]                          \[=\frac{2TA-TA}{2TA}\times 100\]


You need to login to perform this action.
You will be redirected in 3 sec spinner