An electric bulb, when connected across a power supply of 220V, consumes a power of 60W. If the supply drops to 180V, what will be the power consumed? If the supply is suddenly increased to 240V, what will be the power consumed?
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$\text{E}=220\text{v}$ $\text{P}=60\text{w}$ $\text{R}=\frac{\text{V}^2}{\text{P}}=\frac{220\times220}{60}$ $=\frac{220\times11}{3}\Omega$
$=\frac{180\times180\times3}{220\times11}=40.16\approx40\text{w}$
$=\frac{240\times240\times3}{220\times11}=71.4\approx71\text{w}$
- $\text{E}=180\text{v}$
$=\frac{180\times180\times3}{220\times11}=40.16\approx40\text{w}$
- $\text{E}=240\text{v}$
$=\frac{240\times240\times3}{220\times11}=71.4\approx71\text{w}$
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