Question

Anyone can solve this question?

Answer 1

And these are the requirements

Answer 2

Download the attachment in my last post in a similar problem:
http://openstudy.com/study#/updates/4f9a62f5e4b000ae9ecffadb

Then apply the same method.

Answer 3

@Vincent-Lyon.Fr I tried it out but couldn't get the answer. The first step is to set up equations and I think next is to make matrices in order to find the values that are required

Answer 4

Definitely.
You can perform the second step with matrices or simply by eliminating unknowns one after the other.

Answer 5

Yes the problem now is that I couldn't determine the equations yet.

Answer 6

try using superposition theorem
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/suppos.html

Answer 7

First loop goes:\[R _{3}i _{1}+R _{1}i _{1}+R _{4}(i_{1}-i _{2})+R _{5}(i _{1}-i _{3})=0\]Find the other ones.

Answer 8

@Vincent-Lyon.Fr I got the values for the currents and I just need you to check them out for me and tell me what to do next. The values are: i_1 = 9117/403000 approxiamitely 0.25 A, i_2 = 0.613 A, i_3 = 0.722 A

Answer 9

Good work, Ben!
You are brave: I wonder why people who create these problems choose such akward values for resistances and emf? That is nonsense!

Answer 10

I have the same wonder :). And by the way, I know the values but still don't know what to do next? Do you have any idea?

Answer 11

What do you mean? You have these 3 loop-currents so you can work out any current in any branch of the circuit by adding or subtracting.

Then working out powers will be child's play for you!

Answer 12

Yes I know that. If you can check out the requirements one more time. The problem is asking for the current through every resistor. I don't understand what does he mean with that. And also he is asking for the power supplied emf_1 and 2

Answer 13

e.g. current through R1 is i1, but current through R4 is i1-i2

Got it?

Answer 14

It is just Kirchhoff'law for current.

Answer 15

Oh well so i through R1 is i1, i through R2 is i2, through R3 is i1, R4 is i1 - i2, R5 is i1 - i3 and so on right?

Answer 16

Definitely!

Answer 17

Okay that what I have already done right now. And how to calculate the power supplied by emf_1 and 2 and do I need to convert the resultant values because he need the answers in W for power supplied?

Answer 18

??? watt is a unit of power, ampere is a unit of current intensity. The two things are different.

Answer 19

Yes, the unit of power is watt, sorry my bad :). Well anyway how to find the power supplied by V emf_1 and 2? This was the main question.

Answer 20

Don't you know the definition of power released or used by a conductor?

Answer 21

P = (I^2)(R)?

Answer 22

This is ok for a resistor, but the general expression, valid for all conductors is
P = U.I = voltage . current

Answer 23

Well so the summation of voltage for each resistor multiplied by the summation of i_1, i_2 and i_3, right?

Answer 24

For resistors, simply use the formula you wrote earlier.
It is actually P = U.i = (Ri).i = R.i²

Answer 25

Okay thanks a lot for your help