# Is decrease in potential equal to potential difference?

There is a positively charged body, say A, which has a certain potential with respect to the earth. Now, if another negatively charged body, say B, is brought near body A, then its potential will decrease. So my question is: Will this changed potential of A be equal to the potential difference between A and B?

• Could not understand why the potential of A will decrease. You must mention whether the two bodies are connected or not, or are you referring to electrostatic induction, whereby if a negatively charged body and a positively charged body are brought near each other, then the charges are accumulated such that the two surfaces facing each other have equal and opposite charges. – Wrichik Basu Apr 4 '17 at 5:33

## 1 Answer

No it won't. You are comparing two different things

• one is the difference in potential of a body from its potential at an earlier time ($A_{NOW}-A_{THEN}$)
• the other is the difference in potential of two separate bodies ($A_{NOW}-B$)

The only case where these two are equal is if somehow the potential of A before B was brought near it is the same as the potential of B. Otherwise both bodies will acquire new potentials whose difference will have nothing to do with the potential A has lost.