Electrical= Resistance and Energy

Click For Summary

Homework Help Overview

The discussion revolves around a problem in electrical circuits, specifically focusing on resistance and energy transfer in a circuit involving a wire and a battery with internal resistance. Participants are examining how energy is converted from chemical to electrical form and how much of that energy is dissipated as thermal energy in the wire over a specified time period.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the calculation of current and energy transfer, with some questioning the treatment of the battery's internal resistance in the calculations. There is also a focus on the specific energy in the wire versus the total energy in the circuit.

Discussion Status

The discussion is ongoing, with participants sharing their calculations and questioning the assumptions made regarding the internal resistance of the battery. Some have proposed alternative energy values, indicating a lack of consensus on the correct answer.

Contextual Notes

Participants are working under the constraints of a homework problem, which may limit the information available for discussion. The focus is on specific energy calculations over a set time period, and there is an emphasis on clarifying the role of different resistances in the circuit.

Forceflow
Messages
30
Reaction score
0
A wire of resistance 9.0 is connected to a battery whose emf is 3.0 V and whose internal resistance is 1.0 .
(a) How much energy is transferred from chemical to electrical form in 4.0 min?
(b) How much energy appears in the wire as thermal energy in that time?

answer to a= 216 (that's correct)
for b, i got 189.629 (that one is wrong though)

For the work, i did: I= 3V/9 = .3333 A
Vtotal= 3V-IR
Vtotal= 3V-.333(1)
Vtotal= 2.6666
p=Vsquared/R
P=2.666 squared/9
P= .79011
.79011 (4) (60) = 189.62
 
Physics news on Phys.org
When calculating the current -- why would you ignore the resistance of the battery? (Normally you would, but in this case it is a fairly high component of the overall resistance of the circuit)
 
i would ignore it because its asking for the energy in the wire specifically..i believe anyway
 
if for a new answer, i got 194.4 joules..would that be correct?
 
is 194.4 the answer?
 

Similar threads

Electric potential at a point due to two charges
  • · Replies 2 ·
Replies
2
Views
4K
Electric Potential across charging battery.
  • · Replies 5 ·
Replies
5
Views
2K
Electrical Energy Dissipation Across Resistors
  • · Replies 5 ·
Replies
5
Views
13K
High resistance or low resistance for induction cooktops?
  • · Replies 1 ·
Replies
1
Views
3K
RC Circuit - Rate energy is dissipated in the resistor
  • · Replies 4 ·
Replies
4
Views
3K
Potential difference between two points homework
  • · Replies 1 ·
Replies
1
Views
5K
How Does Resistance and EMF Affect Energy Transfer in a Circuit?
  • · Replies 1 ·
Replies
1
Views
4K
The Rate at which kinetic energy changes to thermal energy
  • · Replies 2 ·
Replies
2
Views
2K
Two battery hooked up in series, energy conversion
  • · Replies 3 ·
Replies
3
Views
2K
The rate at which the energy in the wire is transformed into kinetic
  • · Replies 4 ·
Replies
4
Views
2K