BCECE Medical BCECE Medical Solved Papers-2009

  • question_answer
    The current through a bulb is increased by 1%. Assuming that the resistance of the filament- remains unchanged the power of the bulb will

    A)  increase by 1%   

    B)  decrease by 1%

    C)  increase by 2%   

    D)  decrease by 2%

    Correct Answer: C

    Solution :

    Power \[p={{I}^{2}}R\] \[\therefore \] \[p\propto {{I}^{2}}\] Then \[\frac{{{p}_{1}}}{{{p}_{2}}}=\frac{{{I}^{2}}}{{{\left( \frac{101}{100} \right)}^{2}}{{I}^{2}}}\]                 Percentage increase in power \[\left( \frac{{{p}_{2}}}{{{p}_{1}}}-1 \right)%=\left( \frac{101\times 101}{100\times 100}-1 \right)%\] = 2%


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