- #1

- 293

- 39

- Homework Statement
- Calculate the power dissipated in the total circuit

- Relevant Equations
- P = I^2R

Hi guys

I am struggling to find the power dissipated in the total circuit , my answer didn't match the solution in the book

the circuit is simple i used Kirchhoffs rules to find the following :

loop 1 :

$$10-10I_{1}-40I_{3} = 0$$

loop 2:

$$20-20I_{2}-40I_{3} = 0$$

and $$ I_{1}+I_{2}=I_{3}$$

the current through each resistor was

I1 = -0.142857A

I2 = 0.42857A

I3 = 0.2857A

and the the power dissipated in the total circuit is

$$((I1^2)*R1)+((I2^2)*R2)+((I3^2)*R3) = 7.1428W$$

but the books answer is 8.57W

am I doing something wrong ?! or the book is incorrect

I am struggling to find the power dissipated in the total circuit , my answer didn't match the solution in the book

the circuit is simple i used Kirchhoffs rules to find the following :

loop 1 :

$$10-10I_{1}-40I_{3} = 0$$

loop 2:

$$20-20I_{2}-40I_{3} = 0$$

and $$ I_{1}+I_{2}=I_{3}$$

the current through each resistor was

I1 = -0.142857A

I2 = 0.42857A

I3 = 0.2857A

and the the power dissipated in the total circuit is

$$((I1^2)*R1)+((I2^2)*R2)+((I3^2)*R3) = 7.1428W$$

but the books answer is 8.57W

am I doing something wrong ?! or the book is incorrect