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Physics - Current Electricity Question with Solution | TestHub

PhysicsCurrent ElectricityElectrical PowerEasy2 minPYQ_2012

PhysicsEasysingle choice

If voltage across a bulb rated $220 V - 100 W$ drops by $2.5%$ of its rated value, the percentage of the rated value by which the power would decrease isNEET 2012 (Screening)

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Solution:

Power $P = \frac{V ^{2}}{R}$ For small variation $\frac{Δ P}{P} \times 100% = \frac{2 \times Δ V}{V} \times 100% = 2 \times 2.5 = 5%$ Therefore, power would decrease by $5%$ .

Stream:NEETSubject:PhysicsTopic:Current ElectricitySubtopic:Electrical Power

⏱ 2mℹ️ Source: PYQ_2012

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