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What is the amount power going through the following circuit?

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hardworking-h... | (Level 2) eNoter

Posted June 23, 2013 at 6:06 PM via web

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What is the amount power going through the following circuit?

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 23, 2013 at 6:24 PM (Answer #1)

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Power is related to voltage and current by the relation P = V*I = V^2/R. In the circuit, two resistors R1 and R2 are connected in parallel across the voltage source of 10 V. A current of 10 mA flows though the resistor R2. This gives the resistance of R2 as 10/10*10^-3 = 1 k ohm.

The equivalent resistance of R1 and R2 is given by R where 1/R = 1/R1 + 1/R2

=> 1/R = 1/5000 + 1/1000

=> R = 2500/3

The power through the circuit is 10^2/(2500/3) = 0.12 W

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