supply has an emf of 6.0v and internal resistance of 5.0 ohms, it delivers power to TWO external resistors. Maximum power is dissipated in he external resistors when the resistance of them is equal to the internal resistance of the supply. R2 has a resistance of 15 ohms and R1 has resistance 7.5 ohms. Calculate the power dissipated in the 15 ohms resistor when the supply is delivering maximumpower to the external circuit
2007-10-27 05:29:20 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Physics
I don't think this is a hard question.
The resistance of both parallel resistors is (R1*R2)/(R1+R2) = 5 Ω, the same as the internal resistance/resistors.
The emf is distributed half and half (3 and 3 V) between internal and external resistance.
The total current is (6V)/(10Ω)=0.6 A.
The current through R2 is (3 V)/(15 Ω) = 0.2 A.
The power consumed by R2 is (3 V)*(0.2 A) = 0.6 W
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2007-10-27 11:25:56 · answer #1 · answered by oregfiu 7 · 0⤊ 0⤋