Combining Series and Parallel Resistor Combinations

In summary, the conversation discusses finding Rth at the given terminals and the use of series and parallel resistance equations. The attempt at a solution involves combining resistors in series and parallel, but the provided answer starts at a different terminal. The expert suggests studying circuit configurations and provides a suggestion for rearranging the circuit to make it more familiar.
  • #1
hermish
10
0

Homework Statement



Find Rth, at the terminals shown on the diagram


Homework Equations



Series resistance = R1 + R2 + R3 +...
Parallel Resistance = 1/((1/R1)+(1/R2)...))

The Attempt at a Solution



When attempting problems like this, I was told by teachers and the textbook to start at the opposite end of the terminals(where the Rth and arrow is). So in that case I combine the two 6 kohms resistors together (in series), and then combine that with the 3 ohms resistor (in parallel), getting an answer of 2.4 kohms, different to the answer provided.. In the answer provided, they don't start at the opposite end of the terminals, instead they start near the terminals. Is there something I'm not understanding right? or is the answer wrong?
 

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  • #2
you apparently do not understand the concepts of series and parallel. I suggest that you spend time studying circuit configurations until you can identify what is series and what is parallel.
 
  • #3
Remember that the disconnected terminals connected between ends of the 6kΩ resistors can be ignored - you can remove the wire "stubs" on either side of the open circuit completely.

Also the 3kΩ resistor can be rotated counterclockwise by 90 degrees until it's connected to the wire on top.

Redraw the circuit in this fashion. Does it look like a much more familiar arrangement?
 
  • #4
Ok thanks so much for the help I understand now!
 
  • #5


As a scientist, it is important to follow a systematic approach when solving problems. In this case, the approach described in the attempt at a solution is correct - starting from the opposite end of the terminals and combining resistors in series and parallel. It is possible that there may be a mistake in the provided answer, or the diagram may have been labeled incorrectly. It is always important to double check your calculations and refer to the given equations to ensure accuracy. If you are still unsure, you can seek clarification from your teacher or consult with a colleague. Remember, as a scientist, it is important to approach problems with a critical and analytical mindset.
 

1. What is the purpose of combining series and parallel resistor combinations?

The purpose of combining series and parallel resistor combinations is to create a more complex and efficient circuit. By combining resistors in different configurations, we can manipulate the flow of current and voltage in the circuit to meet our specific needs.

2. How do I calculate the total resistance of a series resistor combination?

To calculate the total resistance of a series resistor combination, simply add up the values of each individual resistor. The total resistance is equal to the sum of all the resistors in the series.

3. How do I calculate the total resistance of a parallel resistor combination?

To calculate the total resistance of a parallel resistor combination, use the formula: 1/R(total) = 1/R1 + 1/R2 + 1/R3 + ... + 1/Rn. This formula takes into account the inverse relationship between resistance and current, where as more resistors are added in parallel, the overall resistance decreases.

4. What is the difference between a series and parallel resistor combination?

In a series resistor combination, the resistors are connected one after another, creating a single path for the current to flow through. In a parallel resistor combination, the resistors are connected side by side, creating multiple paths for current to flow through.

5. How can I use series and parallel resistor combinations to control the current and voltage in a circuit?

By combining resistors in different configurations, we can manipulate the flow of current and voltage in a circuit. In a series combination, the total resistance increases and the current decreases, which can be useful for controlling the amount of current flowing through a circuit. In a parallel combination, the total resistance decreases and the current increases, which can be useful for controlling the amount of voltage in a circuit.

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