Electric circuit problem, finding current through a resistor

In summary, the conversation discusses a diagram of an electric circuit with multiple resistors, including R1, R2, and R3. The homework equations and Kirchoff's Laws are mentioned as methods to find the current through each resistor, with the key piece of information being that all of the resistors are in parallel. The conversation ends with a question about finding the net resistance of the circuit.
  • #1
physics604
92
2
1. The diagram attached shows part of an electric circuit. What is the current through resistor R1?

To summarize:
I=6.0 A
R1 = 11.0 Ω
R2 = 33.0 Ω
R3 = 67.0 Ω

R2 and R3 are in parallel, and R1 and R2 and 3 are in parallel.

I know we aren't supposed to attach pictures of questions, but a diagram does make my question a lot easier to understand.


Homework Equations



V=IR
IT in series = I1=I2=I3
IT in parallel = I1+I2+I3
RT in series = R1+R2+R3
RT in parallel = [(1/R1)+(1/R2)+(1/R3)]-1

The Attempt at a Solution



Using the resistor laws, I can find resistance of R2 and 3 by (1/33+1/67)-1.

Using Kirchoff's Laws, I know that the resistance coming out has to equal the 6.0 A.

But I don't get how all this information is relevant. The question doesn't give me voltage or any other information and I don't know how to figure out how much current goes through each resistor.
 

Attachments

  • diagram.PNG
    diagram.PNG
    2.4 KB · Views: 487
Physics news on Phys.org
  • #2
Notice that ALL of the resistors are in parallel. Find the voltage across all of them, then find the current through each one.
 
  • #3
What's the net resistance of the circuit?
 

FAQ: Electric circuit problem, finding current through a resistor

What is the formula for calculating current through a resistor in an electric circuit?

The formula for calculating current through a resistor is Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R), or I = V/R.

How do I determine the direction of current flow in an electric circuit?

The direction of current flow is determined by the direction of the flow of positive charges. In most circuits, current flows from the positive terminal of the power source to the negative terminal.

Can I calculate the current through a resistor using the voltage and current measurements of other components in the circuit?

Yes, the current through a resistor can be calculated using Kirchhoff's Current Law, which states that the sum of currents entering and leaving a junction in a circuit must be equal to 0.

How does the resistance of a resistor affect the current flowing through it?

The resistance of a resistor is directly proportional to the current flowing through it. This means that as resistance increases, current decreases, and vice versa.

What is the unit of measurement for current and how is it typically represented in circuit diagrams?

The unit of measurement for current is the ampere (A), which is equal to one coulomb of charge per second. In circuit diagrams, current is typically represented by the symbol "I".

Back
Top