Current going through my resistors

A

ad353

New Member

• Dec 7, 2004

• #1

hello all!!

i have three resistors that i have in parallel,

they are

120
270
560

what is the current that would be flowing throuh them?

i know you need to use kirchoffs or ohms law, but i jsut dont get it, can any one let me now what the current flowing thrtough them is?

thanks guys

adam


.

 

Styx

Active Member

• Dec 7, 2004

• #2

The current through the 120 Ohm resistor will be := 8333A
The current through the 270 Ohm resistor will be := 3704A
The current through the 560 Ohm resistor will be := 1786A

remember you didnt say what voltage the supply was at

This sounds like homework. Parallel resistor are easy. They all have the same voltage across them and you know what the resistance is, thyus use ohms law to calculate the current flowing through each one

 

A

ad353

New Member

• Dec 7, 2004

• #3

the voltage going in is 10v

i know i have to use sumin like this

Vs = V1 + V2 + V3

Therefore I would have to use

Vs = Vr1 + Vr2 + Vr3

is this on the right line?

adam

 

Styx

Active Member

• Dec 7, 2004

• #4

no!!!!

here is a clue, the voltage I used was 1million volts so frm that, you have the resistance and also the current I calculated.

Work through my calculations to find out what I did

This is a fundemental thing in electronics (Omhs law, Kirchoffs current and voltage law). If you cant get your head round those three and just get the answers you will struggle alot later

 

A

ad353

New Member

• Dec 7, 2004

• #5

ok

so for 10volts

basically

10/120 would give me 0.0833 that would be my current?

adam

 

Styx

Active Member

• Dec 7, 2004

• #6

keep going...

Remeber Kirchoffs current law

"current entering a node must leave that node"

almost there

 

A

ad353

New Member

• Dec 7, 2004

• #7

i getting there


The current through the 120 ohm resistor will be := 0.08333A

The current through the 270 ohm resistor will be := 0.03704A

The current through the 560 ohm resistor will be := 0.01786A


jsut trying to get my head around the next bit of kirchoffs law

adam

 

A

ad353

New Member

• Dec 7, 2004

• #8

so the total current

using kirchoofs current law

is 0.8882a


so that would be how much currentis going through the three resistors in the curcuit?

adam

 

Styx

Active Member

• Dec 7, 2004

• #9

No

you just calculated how much current was going through each resistors. so what is the total current...

REmember kirchoffs current law. := the first current node is the voltage source to the 1st resistor. Current enters that node. Then current leaves that node and goes through the 3 resistors

 

A

ad353

New Member

• Dec 7, 2004

• #10

oh, so that wrong, bacl to the drawing board

i get there in end

adam

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Dec 7, 2004

• #11

The total current is just the sum of the three individual ones, simply add them together - ohms law is all you need to know for this question.

 

Styx

Active Member

• Dec 7, 2004

• #12

Nigel Goodwin said:

The total current is just the sum of the three individual ones, simply add them together - ohms law is all you need to know for this question.

Click to expand...

I was trying to get him to figure it out .
Well good use of my day off sick

 

A

ad353

New Member

• Dec 7, 2004

• #13

so this is basically the total current in the circuit is 0.13823

adam

 

A

ad353

New Member

• Dec 7, 2004

• #14

thanks for your help

adam

 

Styx

Active Member

• Dec 7, 2004

• #15

YES!!!!!!!

but the real question is do you know why?

 

A

ad353

New Member

• Dec 7, 2004

• #16

good point,

not really?

is it because they all flow in the same circuit?

adam

 

jrz126

Active Member

• Dec 8, 2004

• #17

*cough* Energy conservation *cough*