# Find the current and potential difference

#### spice1510

1. Homework Statement
For the circuit shown in the figure, find the current through and the potential difference across each resistor.
http://session.masteringphysics.com/problemAsset/1169464/1/jfk.Figure.23.P60.jpg

2. Homework Equations
V=I(amps)/R(ohms) and Req=R1+R2+R3.....

3. The Attempt at a Solution
Rearranging the circuit:
R(8ohm) and R(24ohm) are parallel so (1/8+1/24)^-1=6ohm
that created a series of R(6ohm)+R(6ohm) so R6+R6=R(12ohm)
now I have the first circuit R(4ohm) in parallel with R(12ohm) and R(24ohm)
(1/4+1/12+1/24)^-1=2.67ohm for equivalent resistance for the entire circuit

24V=I*2.67ohm
I=9Amps

across the 4ohm resistor the current is? I=9A because the current is the same or is it 9A divided across the 3 parallel resistors?

I'm either getting it wrong because I put the 4ohm by itself (before the junction correct?) or if it's in series with the 2 6ohm resistors then that's my error but I've definitely tried it 4 different ways and am getting something wrong.
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution

Related Introductory Physics Homework Help News on Phys.org

#### SammyS

Staff Emeritus
Homework Helper
Gold Member
1. Homework Statement
For the circuit shown in the figure, find the current through and the potential difference across each resistor.
http://session.masteringphysics.com/problemAsset/1169464/1/jfk.Figure.23.P60.jpg

2. Homework Equations
V=I(amps)/R(ohms) and Req=R1+R2+R3.....

3. The Attempt at a Solution
Rearranging the circuit:
R(8ohm) and R(24ohm) are parallel so (1/8+1/24)^-1=6ohm
that created a series of R(6ohm)+R(6ohm) so R6+R6=R(12ohm)
now I have the first circuit R(4ohm) in parallel with R(12ohm) and R(24ohm)

No, the 12Ω and 24Ω are in parallel. The 4V is in series with the (12V & 24V) combination.

(1/4+1/12+1/24)^-1=2.67ohm for equivalent resistance for the entire circuit

24V=I*2.67ohm
I=9Amps

across the 4ohm resistor the current is? I=9A because the current is the same or is it 9A divided across the 3 parallel resistors?

I'm either getting it wrong because I put the 4ohm by itself (before the junction correct?) or if it's in series with the 2 6ohm resistors then that's my error but I've definitely tried it 4 different ways and am getting something wrong.
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
See the comment in red.

#### spice1510

so 4ohm in series with (1/12+1/24)^-1 which equals 8ohm

4ohm+8ohm (series)=12ohm for the entire circuit

24V=12ohm*I
I=2amps

Last edited:

#### SammyS

Staff Emeritus
Homework Helper
Gold Member
so 4ohm in series with (1/12+1/24)^-1 which equals 8ohm

4ohm+8ohm (series)=12ohm for the entire circuit

24V=12ohm*I
I=2amps
Yes.

Now, work your way back through all the resistors.

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