Very simple series circuit question

In summary, the conversation discusses a practice question involving resistors in a circuit. The attempt at a solution involves determining whether the resistors are in series or parallel. It is determined that the resistors on the right side are in series since the current is only flowing through them, while the resistors on the left side are not considered since the switch is open. The differentiation between series and parallel circuits is based on whether the current passes through both resistors or splits between them. The SAT II physics exam is mentioned as a side note.
  • #1
crazybandit
6
0

Homework Statement



http://img2.imageshack.us/img2/6536/physics1.png

Homework Equations



I = V/R, R = R1+R2+R3+...

The Attempt at a Solution



2R+R=3R

V/3R

this is an SAT II physics practice question, i just want to grasp this concept so I am asking for an explanation, i.e. why this is a series circuit (or not?)

oh and how do i know to treat the section with the 1/2 R's as a parallel circuit and not the entire right side? don't they both have parallel resistors? how do i differentiate for circuits in general?
 
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  • #2
Because if S1 is left open then only a closed series circuit with V1R,S2 and 2R is formed.
 
  • #3
rock.freak667 said:
Because if S1 is left open then only a closed series circuit with V1R,S2 and 2R is formed.

so that means i add the 2R and the R to get 3R, hence V/3R, and that the right side is a series circuit? why is it a series circuit if they are parallel to each other? yet the 1/2 R's on the left side are treated as parallel?
 
  • #4
crazybandit said:
so that means i add the 2R and the R to get 3R, hence V/3R, and that the right side is a series circuit? why is it a series circuit if they are parallel to each other? yet the 1/2 R's on the left side are treated as parallel?

It is only because S1 is left open that you can only consider the right side of the circuit only.

Sure the two R/2 resistors are in parallel but since S1 is left open, no current flows through it, so you don't need to consider it.

Only consider where the current is flowing through. Which happens to be through R and 2R since S2 is closed.
 
  • #5
rock.freak667 said:
It is only because S1 is left open that you can only consider the right side of the circuit only.

Sure the two R/2 resistors are in parallel but since S1 is left open, no current flows through it, so you don't need to consider it.

Only consider where the current is flowing through. Which happens to be through R and 2R since S2 is closed.

i know this, but never mind the question, how do i differentiate between a series and a parallel circuit? going back to the question, all the resistors are "parallel" to each other so how can i tell?
 
  • #6
crazybandit said:
i know this, but never mind the question, how do i differentiate between a series and a parallel circuit? going back to the question, all the resistors are "parallel" to each other so how can i tell?

If the same current passes through two resistors, then they are in series. If the current splits, then they are in parallel. I believe that is how it works, though I am not the best at circuit questions.
 
  • #7
rock.freak667 said:
If the same current passes through two resistors, then they are in series. If the current splits, then they are in parallel. I believe that is how it works, though I am not the best at circuit questions.

oh ok, sidenote have you taken the SAT II physics?
 
  • #8
crazybandit said:
oh ok, sidenote have you taken the SAT II physics?

Nope. Only GCE A level physics a few years ago.
 

Related to Very simple series circuit question

1. How do you define a series circuit?

A series circuit is a type of electrical circuit in which the components are connected in a single loop, with the current flowing through each component in a sequence. This means that the same current passes through each component in the circuit.

2. What are the components of a series circuit?

The components of a series circuit include a power source, such as a battery, and resistors, which are used to control the flow of current in the circuit. Other components, such as switches, bulbs, and capacitors, can also be included in a series circuit.

3. What is the total resistance in a series circuit?

In a series circuit, the total resistance is equal to the sum of the individual resistances of each component. This means that the more components added to the circuit, the higher the total resistance will be.

4. How does current flow in a series circuit?

In a series circuit, current flows in a single path from the positive terminal of the power source, through each component, and back to the negative terminal of the power source. This is because the components are connected in a series, with the same current passing through each one.

5. What happens to the current and voltage in a series circuit?

In a series circuit, the current remains constant throughout the circuit, while the voltage is divided among the components. This means that the voltage across each component will be lower than the total voltage of the circuit. Additionally, the total voltage of the circuit is equal to the sum of the individual voltages across each component.

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