Calculating Electric Potential Differences

Click For Summary
SUMMARY

The discussion centers on calculating electric potential differences when an electron moves through an electric field. The work done by the electric field on the electron is 2.00 x 10-19 J. Using the equation ΔV = -W/q, where W is the work done and q is the charge of the electron, it is established that the potential difference V(B) - V(A) is positive due to the negative charge of the electron. This leads to the conclusion that V(B) is greater than V(A), contrary to the initial expectation of a negative result.

PREREQUISITES
  • Understanding of electric potential and electric fields
  • Familiarity with the concept of work done on charged particles
  • Knowledge of the charge of an electron (-1.6 x 10-19 C)
  • Proficiency in using the equation ΔV = -W/q
NEXT STEPS
  • Study the implications of charge polarity on electric potential differences
  • Learn about electric field lines and their relationship to potential energy
  • Explore the concept of work-energy principle in electrostatics
  • Investigate how to calculate potential differences in multi-charge systems
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone studying electrostatics, particularly those focusing on electric potential and the behavior of charged particles in electric fields.

G-reg
Messages
41
Reaction score
0

Homework Statement


When an electron moves from A to B along an electric field line in the figure below, the electric field does 2.00 10-19 J of work on it.

What are the electric potential differences:
(a) VB - VA

(b) VC - VA

(c) VC - VB


Homework Equations


Ok so I know that the equation to use in this case is that of, \DeltaV = \frac{-W}{q}


The Attempt at a Solution


I understand how to choose the equation I've chosen and how to get the right answer. What I don't understand is why the answers to (a) and (b) aren't negative when the equation shows that they should. Can anyone help?
 
Physics news on Phys.org
I don't have all the problem details (not enough to actually work out the problem). But allow me to speculate: Forgot the negative charge of the electron maybe? :wink: There's enough information for me to do the first part.

The given wording was "When an electron moves from A to B [...] the electric field does [positive value] J of work on it."

If the above statement applied to a test charge it means the V(A) is greater than V(B). But we're not dealing with a positive test charge. We are dealing with a negative electron :cool:. So given the negative charge, the statement implies, V(B) is greater than V(a). Therefore,

V(B) - V(A) is positive.
 
Last edited:

Similar threads

Replies
1
Views
2K
Replies
5
Views
1K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
Replies
6
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 5 ·
Replies
5
Views
1K
Replies
3
Views
2K