Electric Field Due to Disk and Infinitely Large Sheet

Q. For the given electric field lines configurations, which of the following charge has greater magnitude?

1. $Q_1$
2. $Q_2$
3. $Q_4$
4. $Q_3$

Q. 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)

1. $\left(\frac{q}{2A{\epsilon }_0}\right)$
2. $\left(\frac{2q}{2A{\epsilon }_0}\right)$
3. \N
4. $\left(\frac{4q}{2A{\epsilon }_0}\right)$

Q. For the given electric field lines configurations, which of the following charge has greater magnitude?

1. $Q_2$
2. $Q_3$
3. $Q_4$
4. $Q_1$

Q.
Electric field close to plane of charge is shown in figure. External electric field in V/m is

Q.

A square plate of side 2 m contains a charge uniformly distributed over one of its side, such that the surface charge density $\sigma$ is $10C/m^2$. The net charge on the square surface is n coulombs, where n is a natural number. The value of n is __.