Solving Battery & Current Homework Problem: V, i, R, Power, Energy

  • Thread starter Thread starter Zonda
  • Start date Start date
  • Tags Tags
    Battery Current
Click For Summary

Homework Help Overview

The problem involves analyzing a circuit with multiple batteries and resistances, specifically focusing on calculating current, power, and energy interactions within the circuit. The context is rooted in electrical circuits, particularly involving Ohm's law and power calculations.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the method of combining resistances in series and parallel to simplify the circuit. Questions arise regarding the correct resistances to use for calculating current and power for each battery. There is also uncertainty about how to apply the voltage values in relation to the resistances.

Discussion Status

The discussion includes attempts to clarify the approach to the problem, with some participants offering guidance on combining resistances and setting up equations. However, there is no explicit consensus on the calculations, and one participant indicates they have resolved their issue independently.

Contextual Notes

Participants mention specific voltage values and resistance configurations but express uncertainty about the calculations involved. The original poster seeks assistance primarily for parts (a) and (b) of the problem, indicating a need for foundational understanding before proceeding to subsequent parts.

Zonda
Messages
13
Reaction score
0

Homework Statement


Please help!:confused:

My problem is: (with figure attached, the figure explains the majority of the ptorblem)
(a) What is the size and direction of current i1 in Fig. 27-40, where each resistance is 2.2 and V1 = 18 V?

(b) What is the power of the 18 V battery, and is energy being supplied or absorbed by the battery?

(c) What is the power of the 10 V battery, and is energy being supplied or absorbed by the battery?

(d) What is the power of the 5.0 V battery, and is energy being supplied or absorbed by the battery?

Homework Equations


V=iR

The Attempt at a Solution


For part (a) I'm having trouble firguring out which resistances to use. Do I use all of the resistances and add them up according to whether they are parallel or perpendicular? Then, when I get the resistance that I need, do I just use the 10 V battery as my voltage to calculate the current? I tried adding all of the resistances and I got 8.64 ohms. Is this correct?

For part (b) I need to know again what resistance to use to calculate the current, which I would need to calculate power. If I can get some help on (b), I can probably do (c) and (d) by myself.
 

Attachments

  • W0625-Nalt.jpg
    W0625-Nalt.jpg
    7 KB · Views: 453
Physics news on Phys.org
In general, the best place to start such problems is to compute your lump resistances together whenever possible using the rules for addition in series and parallel. Then redraw the diagram with these. In this case you should end up with three R's and three voltages. Then one can start to develop some meaningful equations which will answer all of the above questions. Out of curiosity, what course is this for?
 
This is for Physics II. I understand how to lump the resistances together, i.e. parrallel and perpendicular. However, I am not sure how to calculate the amps. For example, for the left side, do I take the 5 volts and divide it by 0.88 ohms and then add that to 10 volts divided by 3.3 ohms (the resistance at the bottom left and bottom of the picture?
 
Nevermind. I figured out the problem.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
2K
Replies
7
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
784
  • · Replies 24 ·
Replies
24
Views
6K
  • · Replies 2 ·
Replies
2
Views
705