Electrical circuits: when all switches are closed, what is R?

In summary, the conversation is about a circuit with two switches and four resistors, where the question is asked about the total resistance when both switches are closed. The person asking is unsure about which resistors are connected in parallel and series and has attempted to solve the problem using the equation 1/R(T) = 1/R1 + 1/R2 + 1/R3 + 1/R4. The person provides a diagram and asks for advice on identifying the parallel and series connections. A hint is given to help with identifying the connections.
  • #1
GreenTea09
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0

Homework Statement


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When both switches 1 and 2 are closed,what is the total resistance of the set up? I couldn't figure out which resistors are connected in parallel and which resistors are actually in series in this set up when both swtiches are closed. I trace back to the original current source to see if there is any splitting of the current at each section and there is, and from there i conclude they are all connected in parallel and the attempt at my solution is to calculate the total resistance of the resistors as if they are all connected in parallel. My final results in 7.5 Ohms. According to answer sheet, the correct answer should be 2.5 Ohms. The problem lies in my parallel/series circuit identification. Can anyone please advise which resistors are connected in parallel or series?

Homework Equations


1/R(T) = 1/R1 + 1/R2 + 1/R3 + 1/R4

The Attempt at a Solution


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  • #2
Look carefully at what S1 does to the left hand resistor, and what S2 does to the right-hand resistor.
 
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  • #3
Hint: What happens in a circuit when a wire is in parallel with a resistor?
 
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FAQ: Electrical circuits: when all switches are closed, what is R?

1. What is the purpose of switches in an electrical circuit?

The switches in an electrical circuit are used to control the flow of electricity. When they are closed, they allow current to flow through the circuit, and when they are open, they stop the flow of current.

2. How do closed switches affect the resistance (R) in an electrical circuit?

When all switches in an electrical circuit are closed, the resistance (R) is reduced. This is because the closed switches create a shorter path for the current to flow, decreasing the overall resistance in the circuit.

3. What is the relationship between resistance (R) and current (I) in an electrical circuit?

The relationship between resistance (R) and current (I) in an electrical circuit is described by Ohm's Law, which states that the current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance. In other words, as resistance increases, current decreases.

4. How does the number of closed switches affect the resistance (R) in a series circuit?

In a series circuit, the total resistance (R) increases when more switches are closed. This is because the closed switches create more resistive elements in the circuit, making it more difficult for current to flow.

5. What happens to the flow of current when all switches in a parallel circuit are closed?

When all switches in a parallel circuit are closed, the overall resistance (R) is decreased and the flow of current increases. This is because closing the switches creates multiple paths for the current to flow through, reducing the overall resistance in the circuit.

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