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Question
The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4 Ω, what is the maximum current that can be drawn from the battery?
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Solution
Emf of the battery, E = 12 V
The internal resistance of the battery, r = 0.4 Ω
The maximum current drawn from the battery is I.
According to Ohm’s law,
E = Ir
I = `E/r`
= `12/0.4`
= 30 A
The maximum current drawn from the given battery is 30 A.
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