Question

When an object with a negative charge is moved from point A to point B through an external electrical field, it gains electrical potential energy. When an object with positive charge is moved from point A to point B though the same field, it loses electrical potential energy. Which of the following statements is true? Select all that apply.
A:Because the positive and negative charges cancel out, the potential difference between A and B is zero (that is, VB = VA).

B:The positively charged object moves through a negative potential difference between A and B (that is, VB - VA < 0).

C:The negatively charged object moves through a negative potential difference between A and B (that is, VB - VA < 0).

D: The negatively charged object moves through a positive potential difference between A and B (that is, VB - VA > 0).

E:The positively charged object moves through a positive potential difference from A and B (that is, VB - VA > 0).

-An explanation would be appreciated, thank you!

Answer 1

Explanation:

As per the problem,

           $\Delta U = (V_{B} - V_{A})(-q) > 0$

When q > 0 then -q is a negative charge . Since, change in potential energy ($\Delta U$) increases.

or,     $(V_{A} - V_{B})q$ > 0

or,      $V_{A} > V_{B}$

Therefore, both positive and negative charge will move from $V_{A}$ to $V_{B}$ and as $V_{B} < V_{A}$ so both of them move through a negative potential difference.

Thus, we can conclude that the true statements are as follows.

• The positively charged object moves through a negative potential difference between A and B (that is, VB - VA < 0).

• The negatively charged object moves through a negative potential difference between A and B (that is, VB - VA < 0).