Physics - Current Electricity Question with Solution | TestHub

PhysicsCurrent ElectricityElectrical PowerMedium2 minQB

PhysicsMediumsingle choice

A cell of internal resistance $r$ drives current through an external resistance $R .$ The power delivered by the cell to the external resistance will be maximum when:

Options:

Answer:

Solution:

Current $i = \frac{E}{r + R}$
Power generated in $R$

$P = i^{2} R$
$P = \frac{E ^{2} R}{( r + R ) ^{2}}$

for maximum power $\frac{d P}{d R} = 0$
$E^{2} [\frac{( r + R ) ^{2} \times 1 - R \times 2 ( r + R )}{( r + R ) ^{4}}] = 0$
$\Rightarrow when, r = R then, \frac{d P}{d R} = 0$

Stream:JEESubject:PhysicsTopic:Current ElectricitySubtopic:Electrical Power

⏱ 2mℹ️ Source: QB

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