Electric field from potential energy

AI Thread Summary
In a uniform electric field scenario, the potential at points (0,0) and (.5,0) is 20V higher than at (0,.5). The correct answer for the magnitude and direction of the electric field is 40 N/C in the positive j direction. The electric field points in the direction of decreasing potential, confirming that it must be upward. The potential difference of 20V corresponds to the electric field strength calculated using the formula E = V/d. Understanding that the field is perpendicular to the x-axis due to constant potential along that axis is also crucial.
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Homework Statement



Consider uniform electric field. The values of the potentials at the points(0,0) (.5,0) are equal and 20V higher than the potential at (0,.5) The magnitude and direction of the electric field are:
a)0
b)40N/c j
c)-40N/c j


Homework Equations





The Attempt at a Solution


I know the answer is b because this is a problem for my exam review and we were given the solutions, I don't know how to get it though can anyone help?
 
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I think I know why. I am thinking that since the field points in the direction of decreasing potential it must go up and since Va-Vb = E(b)-E(a) you know the potential difference is 20. so 20=E(.5) (a=0) then divide out and get 40n/c j. Also you know that the field must be perpendicular to the x-axis because as you move down the x-axis the potential remains constant right? Can anyone verify this I have an exam tomorrow and I want to make sure I have the concepts right. Thanks.
 
You're reasoning is correct.
 
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