Equivalent resistance of a circuit

In summary, the problem involves finding the equivalent resistance of a circuit with resistors of varying values and determining the current flowing through a specific resistor using the equation I = V/R. The equivalent resistance is calculated to be 25 Ohms and the current through the entire circuit is 4 Amps, but further calculations are needed to find the current through the specific resistor.
  • #1
dewdrop714
17
0
1. The problem statement

http://s685.photobucket.com/albums/vv212/dewdr0p714/?action=view&current=3circuitontakehometest1.jpg

The voltage is on the left (100V) and the jagged lines are the resistors in Ohms. I need to find the equivalent resistance of the circuit and after that the current flowing through the 4 ohm resistor.

2. Homework Equations

I = V/R


3. The Attempt at a Solution

I'm not sure if I calculated these correctly...

Equiv Resistance = 7 + (10/2) + 8 + (4/2) + 3 = 25 Ohms.

For the current flowing through the 8 ohm resistor, I = V/R = 100V/25ohms = 4 Amps
 
Last edited:
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  • #2
Welcome to PF!

Hi dewdrop714! Welcome to PF! :smile:
dewdrop714 said:
The voltage is on the left (100V) and the jagged lines are the resistors in Ohms. I need to find the equivalent resistance of the circuit and after that the current flowing through the 4 ohm resistor.
…
Equiv Resistance = 7 + (10/2) + 8 + (4/2) + 3 = 25 Ohms.

Looks good! :biggrin:
For the current flowing through the 8 ohm resistor, I = V/R = 100V/25ohms = 4 Amps

8 ohm? :confused:

Anyway, that's the current through the whole circuit … you need the current flowing through just the bit of wire containing the 4(?) ohm resistor. :wink:
 

1. What is equivalent resistance?

Equivalent resistance is the total resistance of a circuit when all resistors are combined. It represents the overall resistance that the current experiences as it flows through the circuit.

2. How is equivalent resistance calculated?

Equivalent resistance is calculated by adding up the individual resistances in a series circuit or by using the formula 1/Req = 1/R1 + 1/R2 + 1/R3... for a parallel circuit.

3. Why is equivalent resistance important?

Equivalent resistance is important because it helps us determine the total current and voltage in a circuit. It also allows us to simplify complex circuits into a single equivalent resistance, making it easier to analyze and understand.

4. How does the placement of resistors affect the equivalent resistance?

In a series circuit, resistors are placed in a line, so the equivalent resistance is simply the sum of all the individual resistances. In a parallel circuit, resistors are placed side by side, so the equivalent resistance is less than the smallest individual resistance.

5. Can equivalent resistance ever be greater than the individual resistances?

No, equivalent resistance can never be greater than the individual resistances. In a series circuit, the equivalent resistance is always equal to the sum of the individual resistances. In a parallel circuit, the equivalent resistance is always less than the smallest individual resistance.

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