Loop Rule - Batteries and Resistors

AI Thread Summary
The discussion focuses on solving a circuit problem involving two batteries and three resistors using Kirchhoff's Rule. The user has set up equations for two loops, labeling the batteries and currents for clarity. They express uncertainty about the next steps in solving the equations. After receiving feedback, they mention having worked through the problem with their teacher's assistance. The conversation highlights the importance of proper labeling and understanding loop rules in circuit analysis.
ihearyourecho
Messages
61
Reaction score
0

Homework Statement



Two batteries and three resistors are connected as shown in the figure .
http://session.masteringphysics.com/problemAsset/1122583/1/Walker.21.52.jpg

A) How much current flows through 6.0 V battery when the switch is closed?
B) How much current flows through 9.0 V battery when the switch is closed?
C) How much current flows through 6.0 V battery when the switch is open?
D) How much current flows through 9.0 V battery when the switch is open?


Homework Equations



Kirchoff's Rule

The Attempt at a Solution



I broke it down into two different loops, the one on the left and the one on the right. I labeled the 6V battery as E1 and the 9V one as E2. I called the current flowing upward from 6V I1 and the current flowing upward from 9V I2. I labeled the resistor under the 6V battery R1 and the resistor under the 9V battery R2.

From this, here are my equations:

For Loop 1:
E1-E2-I1R1+I2R2=0

For Loop 2:
E2-I3R3-I2R2=0

Both of these due to Loop Rule.

I'm not sure where to go from here, or even if these are totally correct.

Help would be great :)
 
Physics news on Phys.org
Hi ihearyourecho! :smile:

(try using the X2 tag just above the Reply box :wink:)

An equation relating I1 I2 and I3 would be pretty cool. :rolleyes:
 
After sitting down with my teacher and getting some help from him, I was able to crank through the problem. Thanks for the tip about super and subscripts though!
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How to solve this chain with Kirchhoff's laws?
Replies
18
Views
3K
Why do the headlights on the car become dim when the car is starting?
Replies
4
Views
2K
Sign conventions for Kirchhoff's loop rule
Replies
7
Views
1K
A circuit involving two non-linear resistances (incandescent lamps)
Replies
14
Views
2K
Circuit is constructed with six resistors and two batteries
Replies
2
Views
2K
Grounded circuit, 2 batteries and 2 resistors
Replies
6
Views
2K
Circuit analysis: Six resistors and two batteries
Replies
1
Views
2K
Two batteries and three resistors
Replies
1
Views
5K
What is the potential at the top of R2 in this circuit?
Replies
16
Views
4K
3 loop circuit, 5 resistors, 2 batteries
Replies
20
Views
6K

Hot Threads

Recent Insights

Back
Top