Current through resistor

In summary, the current through the 2 ohm resistor is 4 A and the current through the 8 ohm resistor is 1 A, with a potential difference of 8 V in both cases. This is based on the Kirchoff's junction rule and the equations +8V-2I_1=0 and -8V-8I_2+16V=0.
  • #1
fish
49
0
what is the current through the 2 ohm resistor?
what is the current through the 8 ohm resistor?


8 V
...! |...
. empty space .
. empty space . I
. empty space .
...2 ohm Res...
. empty space .
. empty space 8 ohm Res
. empty space . I_2
. empty space .
...! |...
16 V

! = (-) side of battery
| = (+) side of battery

I_1 is on the 2 ohm branch (current going left to right)
I current going down (clockwise)
I_2 current going down (clockwise)

Is this setup right with correct sign conventions?

I_2=I+I_1

2 ohm res:
+8V-2I_1=0
8=2I_1
I_1=4 A

8 ohm res:
-8V-8I_2+16V=0
8V=8I_2
I_2=1 A
 
Physics news on Phys.org
  • #2
Originally posted by fish
what is the current through the 2 ohm resistor?
what is the current through the 8 ohm resistor?


8 V
...! |...
. empty space .
. empty space . I
. empty space .
...2 ohm Res...
. empty space .
. empty space 8 ohm Res
. empty space . I_2
. empty space .
...! |...
16 V

! = (-) side of battery
| = (+) side of battery

I_1 is on the 2 ohm branch (current going left to right)
I current going down (clockwise)
I_2 current going down (clockwise)

Is this setup right with correct sign conventions?

I_2=I+I_1

This is correct by Kirchoff's junction rule.


2 ohm res:
+8V-2I_1=0
8=2I_1
I_1=4 A

8 ohm res:
-8V-8I_2+16V=0
8V=8I_2
I_2=1 A

Yes, this is correct. The potential difference in a circuit loop is equal to zero.
However a more correct way to present your answer would be:

[tex]8V-I_1(2\Omega)=0[/tex]
[tex]8V=I_1(2\Omega)[/tex]
[tex]I_1=4A[/tex]


[tex]-8V-I_2(8\Omega)+16V=0[/tex]
[tex]8V=I_2(8\Omega)[/tex]
[tex]I_2=1A[/tex]

It's good practice to keep units in your work.
 
  • #3
thanks redrogue
 

What is current?

Current is the flow of electric charge or the movement of electrons through a conductor. It is measured in amperes (A).

What is a resistor?

A resistor is a passive electronic component that resists the flow of electric current. It is typically made of a material that has high resistance, such as carbon or metal, and is used to control the amount of current flowing in a circuit.

What is Ohm's law?

Ohm's law states that the current through a resistor is directly proportional to the voltage across it and inversely proportional to its resistance. This means that as the voltage increases, the current will also increase, but as the resistance increases, the current will decrease.

How is current through a resistor calculated?

The current through a resistor can be calculated using Ohm's law (I = V/R), where I is the current in amperes, V is the voltage in volts, and R is the resistance in ohms. Alternatively, the current can also be calculated using the formula I = P/V, where P is the power in watts and V is the voltage in volts.

What factors affect the current through a resistor?

The current through a resistor is affected by the voltage applied across it, the resistance of the resistor, and the type of material the resistor is made of. The temperature of the resistor can also affect its resistance, and therefore, the current flowing through it.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
811
  • Introductory Physics Homework Help
Replies
1
Views
666
  • Introductory Physics Homework Help
Replies
16
Views
1K
  • Introductory Physics Homework Help
2
Replies
42
Views
866
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
6
Views
659
  • Introductory Physics Homework Help
Replies
1
Views
402
  • Introductory Physics Homework Help
Replies
8
Views
2K
Replies
2
Views
383
Back
Top