Question

Three identical conduting plates $P_1,P_2\text{and}{P}_3$ are kept at a distance $d$ from each other as shown. If $q,-q,2q$ are the charges in $P_1,P_2\text{and}{P}_3$ respectively, the electric field between $P_1\text{and}{P}_2$ is (where $A$ is the area of plate)

• A. $\left(\frac{q}{2A{\epsilon }_0}\right)$
• B. $\left(\frac{2q}{2A{\epsilon }_0}\right)$
• C. 0.0
• D. $\left(\frac{4q}{2A{\epsilon }_0}\right)$

Answer 1

The correct option is C 0.0


The electric field at any point outside of conducting plate is $E=\frac{\sigma }{2{\epsilon }_0}=\frac{Q}{2A{\epsilon }_0}$
where $Q$ is charge on plate and $A$ is area of it.
Here, the field between $P_1$ and $P_2$ is
$=\frac{1}{2A{\epsilon }_0}[q-(-q+2q\left)\right]=0$