Why Does Moving a Negative Charge to a Higher Potential Increase Its Energy?

AI Thread Summary
Moving a negative charge from point A to point B increases the system's potential energy by 10J, leading to the equation U=qV. For a charge of -2C, this results in the equation 10=(-2)V, which simplifies to V= -5V. However, since the negative charge gains energy, point A must have a higher potential than point B, indicating that V(ab) is +5V. This illustrates that a negative charge moving to a higher potential results in increased energy, confirming the relationship between charge movement and electric potential. Understanding this concept is crucial for solving related physics problems.
Kelly McGuire
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Homework Statement


When a -2C is moved from point A to B, the potential energy of the system increases by 10J. What is the voltage V(ab)?

Homework Equations


U=qV

The Attempt at a Solution


10=(-2)V, I thought the voltage was -5V but the correct answer is +5V. Could someone explain why this is?
 
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Kelly McGuire said:
What is the voltage V(ab)?
Vab is nothing but Va-Vb. In simple words, if you have a positive charge and a negative charge placed close to each other, you'll observe a gain in potential energy of the negative charge if it is moved away from the positive charge. Here, since the negative charge is gaining energy, point A must be at a higher potential (more +ve than B) than point B. Hence, Vab= +5V.
 

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