Solving Resistor Circuits: Find Currents in R & 10Ω Resistors

In summary, to find the current in the 10Ω resistor, use Kirchhoff's Voltage Law (KVL) to find the voltage drop across the 2Ω resistor. Then, use Ohm's Law (V=IR) to find the current through the 10Ω resistor.
  • #1
Angie K.
108
1

Homework Statement



P26_29.jpg
The resistor R in the above figure has a resistance of 19.1 Ω.

a. Find the current in the resistor R.

b. Find the current in the 10-Ω resistor.

2. Homework Equations


Kirchhoff's Laws (Junction Rule and Loop Rule)

V=IR

The Attempt at a Solution


I figured out part a (I got 0.2844 A) and got it right.
I am not sure how to go about finding the current of the 10 Ohm resistor.
I know current flows through the path of least resistance.

I tried finding the voltage of the resistor R (because I have the current and the Resistance) and that's 5.43204 V and then using that same voltage (because for resistors in parallel, the voltage is the same) to figure out the current of the 10 Ohm resistor. (5.43204V/10Ohms=.543204 A) Which is the wrong answer.

Someone please clarify where I need to go from the information that I already have.
 
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  • #2
Be careful when you say "voltage of the resistor R". You actually mean the voltage drop (ie. voltage difference between the ends) is 5.43204. That means the other end (where the 10Ω is connected) is at 6 - 5.43204 = 0.56796V. You'll also need to find the voltage at the other end of the 10Ω to calculate the voltage drop, and only then can you calculate the current.
 
  • #3
I meant the voltage drop. Sorry about that.

So that just gives me 5.43204 as the voltage drop of the other end and dividing by 10Ohms = .543204 Amps.
The one end has the voltage drop of .56796V and dividing that by 10Ohms , I get .056796 So now what do I do?
 
  • #4
Angie K.-- use the KVL to find Voltage drop across the 2Ω resistor & then find the current through same. etc.
 
Last edited by a moderator:

1. What is a resistor circuit?

A resistor circuit is a network of resistors that are connected together in a specific pattern. These circuits are used to control the flow of electric current and can be found in many electronic devices.

2. How do I find the current in a resistor circuit?

To find the current in a resistor circuit, you will need to use Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). So, I = V/R. You will also need to use Kirchhoff's Current Law, which states that the sum of all currents entering and exiting a node in a circuit must be equal to 0.

3. What are the steps for solving a resistor circuit?

The steps for solving a resistor circuit are as follows:

  1. Draw the circuit and label all known values.
  2. Use Ohm's Law and Kirchhoff's Current Law to create equations for each node in the circuit.
  3. Solve the equations simultaneously to find the unknown currents.
  4. Check your solution by using Kirchhoff's Voltage Law, which states that the sum of all voltage drops in a closed loop must be equal to the sum of all voltage sources.

4. What are the units for resistance?

The unit for resistance is ohms (Ω). This unit is named after the German physicist Georg Ohm, who discovered the relationship between current, voltage, and resistance.

5. Can I use the same method to solve any resistor circuit?

Yes, the same method can be used to solve any resistor circuit, no matter how complex it may seem. However, for more complicated circuits, you may need to use other laws, such as Kirchhoff's Voltage Law and Ohm's Law for series and parallel circuits.

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