Voltage in series and parallel circuits

In summary: Points that are connected in a series circuit (like the points in the diagram) share the same voltage, while in a parallel circuit the voltages at different points are not always equal. This is because the voltage between any two points does not depend on the path taken.
  • #1
johnathon
40
0
Why is it that in a series circuit the sum of the voltages across the components is equal to the voltage supplied by the battery but in parallel the voltages are equal for different branches in the circuit?
 
Physics news on Phys.org
  • #2
hi johnathon! :smile:
johnathon said:
Why is it that … in parallel the voltages are equal for different branches in the circuit?

because the voltage between any two points does not depend on the path taken :wink:
 
  • #3
johnathon said:
Why is it that in a series circuit the sum of the voltages across the components is equal to the voltage supplied by the battery but in parallel the voltages are equal for different branches in the circuit?

I must not be understanding your question because to me your question sounds exactly like "why is the voltage across a battery equal to the voltage across the battery"
 
  • #4
phinds said:
I must not be understanding your question because to me your question sounds exactly like "why is the voltage across a battery equal to the voltage across the battery"

What I was asking is if there're three branches, why isn't the voltage across each branch equal to 1/3 of the supplied voltage?
 
  • #5
johnathon said:
What I was asking is if there're three branches, why isn't the voltage across each branch equal to 1/3 of the supplied voltage?

Because the voltage across the battery is the voltage across the battery. What you hook up to it is irrelevant (other than a short circuit).
 
  • #6
Hi johnathon

have a look at this circuit...

attachment.php?attachmentid=43390&stc=1&d=1328146169.gif


Q --what do you notice about points 1,2,3 and 4 ?

A -- They are all connected in common to the positive terminal of the battery
just as points 5,6,7 and 8 to the negative terminal
The fact that they are all commoned, means that they MUST be at the same voltage potential

Now with the current flowing in the circuit that's different. Because the resistors are of different values, the current flow through each resistor will be different
knowing the voltage across and the value of each resistor you can use Ohms Law and work out the current flowing through each resistance branch
and therefore the total current flowing in the circuit. The total current will be equal to the sum of the flow through each resistor.


cheers
Dave
 

Attachments

  • 00092.GIF
    00092.GIF
    3.2 KB · Views: 1,131
  • #7
In circuit diagrams, conductors are treated as perfect conductors (zero resistance), so the voltage at any point on an idealized conductor is constant.
 

FAQ: Voltage in series and parallel circuits

What is the difference between series and parallel circuits?

In a series circuit, the components are connected in a single loop, meaning the current flows through each component in order. In a parallel circuit, the components are connected in multiple branches, meaning the current splits and flows through each component independently.

How does voltage behave in series and parallel circuits?

In a series circuit, the voltage drops across each component add up to the total voltage of the circuit. In a parallel circuit, the voltage remains the same across each branch.

What is the total voltage in a series circuit?

The total voltage in a series circuit is equal to the sum of the individual voltage drops across each component.

How is total resistance calculated in a parallel circuit?

In a parallel circuit, the total resistance is calculated using the formula 1/Rt = 1/R1 + 1/R2 + 1/R3 + ..., where Rt is the total resistance and R1, R2, R3, etc. are the individual resistances in each branch.

What happens to the overall resistance in a parallel circuit when more resistors are added?

Adding more resistors in parallel decreases the overall resistance of the circuit, as the total resistance is calculated by adding the reciprocals of each individual resistance. This means that the more branches there are, the lower the total resistance will be.

Back
Top