Calculating Total Resistance in a Series-Parallel Circuit

Click For Summary
To calculate the total resistance in a series-parallel circuit, the formulas for resistors in series and parallel are essential: RT = r1 + r2 + r3... for series and 1/RT = 1/r1 + 1/r2 + 1/r3... for parallel. In the discussed circuit, two 1-ohm resistors are in series, while two 2-ohm resistors are in parallel since the current splits between them. The total resistance for the series portion is 2 ohms, and the parallel portion requires calculating the combined resistance of the 2-ohm resistors. Understanding the flow of current is crucial; resistors in series have the same current, while those in parallel share the same voltage. The discussion emphasizes applying these principles to solve for total resistance effectively.
Theman123
Messages
8
Reaction score
0

Homework Statement



I am asked to calculate the total resistance of this circuit


2dwck6h.jpg

Homework Equations


1/rt =1/r1+1/r2+1/r3...etc - parallel
RT=r1+r2+r3...etc - series

The Attempt at a Solution


1/rt = 1/2 +1/2 +1/1
rt=1/2
then i tried adding 2 to it (from the top two resistors added together in series i think...)
rt=2.5
 
Physics news on Phys.org
I can't follow your post but let's start from the right and with some basics.

If the same current flows through two resistors, they are in series.

If the same voltage is across two resistors, they are in parallel.

Current splits when it flows into a node.

Now, at the right hand side, we have a a 1 ohm and 1 ohm resistor. Does the same current flow through them?

Yes, meaning they are in series. Now, this 2 ohm resistor and the 2 ohm resistor. There is a current coming in from the left hand branch, which splits between the 2 ohm and 2 ohm resistor, meaning they are not in series. Add these two in parallel.

Try and finish the rest of the question yourself, using these basics. If you've any questions ask.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 60 ·
3
Replies
60
Views
10K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 14 ·
Replies
14
Views
1K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 19 ·
Replies
19
Views
7K