question_answer

Two conducting plates P and Q with large surface area A are placed as shown in figure. A charge q is given to plate P. The electric field between the plates at any point is:

A)  \[\frac{q}{3A{{\varepsilon }_{0}}}\]

B)  \[\frac{q}{2A{{\varepsilon }_{0}}}\]

C)  \[\frac{q}{A{{\varepsilon }_{0}}}\]

D)  \[\frac{2q}{A{{\varepsilon }_{0}}}\]

Correct Answer: B

Solution :

Charge distribution will be as shown Field at a point in between two plates, Due to  \[{{Q}_{B}},\]  \[{{E}_{Q}}=\frac{q-q'}{2A{{\varepsilon }_{0}}}\] Net field at that point, \[E={{E}_{Q}}+{{E}_{P}}\] \[=\frac{q-q'}{2A{{\varepsilon }_{0}}}+\frac{q'}{2A{{\varepsilon }_{0}}}\] \[\Rightarrow \] \[E=\frac{q}{2A{{\varepsilon }_{0}}}\]