NEET-XII-Physics
33: Thermal and Chemical Effects of Electric Current
- #8An electric bulb marked 220 V, 100 W will get fused if it is made to consume 150 W or more. What voltage fluctuation will the bulb withstand?Ans : Given that the operating voltage is V and power consumed is P.
Therefore, the resistance of the bulb,
`` R=\frac{{V}^{2}}{P}=\frac{(220\times 220)}{100}=484\,\mathrm{\,\Omega \,}``
`` ``
The power fluctuation, p = 150 W. So, the voltage fluctuation that the bulb can withstand,
`` v=\sqrt{pR}=\sqrt{150\times 484}``
`` =269.4\,\mathrm{\,V\,}=270\,\mathrm{\,V\,}``
The bulb will withstand up to 270 V.
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