0

I had a doubt about why inside a capacitor having equal and opposite charges on both plates have a electric field $Q/A€$ and not $2Q/A€$ (where $€$ stands for permittivity).

But a question at stack exchange answer this by saying that superposition will not apply for when electric field terminate at the negative charge

https://physics.stackexchange.com/a/65194/291481

i want to know why not the same concept is applied in this case of infinitely long line charges having opposite charges

why we are using superposition to find electric field at a point between the two line charges

enter image description here

Qmechanic
  • 220,844
Samardeep singh
  • 115

1 Answers1

1

As @verdelite suggest, the electric field from the positive (or negative) charges is $Q/(2A\epsilon_0)$ (i.e. the electric field of infinity uniform charged plate) and using superposition principle (note that this is just a fancy name for electric field additivity) the total electric field is $Q/(2A\epsilon_0)$.

Ziv Landau
  • 1,783