In the following four situations charged particles are at equal distance from the origin. Arrange them the magnitude of the net electric field at origin greatest first

The direction $(\theta ) $ of $\vec E$ at point $P$ due to uniformly charged finite rod will be

The three charges $q / 2, q$ and $q / 2$ are placed at the corners $A , B$ and $C$ of a square of side ' $a$ ' as shown in figure. The magnitude of electric field $(E)$ at the comer $D$ of the square, is

The point charges $Q$ and $-2Q$ are placed at some distance apart. If the electric field at the location of $Q$ is $\vec E$  , then the electric field at the location of $-2Q$ will be :

Two point charges $A$ and $B$ of magnitude $+8 \times 10^{-6}\,C$ and $-8 \times 10^{-6}\,C$ respectively are placed at a distance $d$ apart. The electric field at the middle point $O$ between the charges is $6.4 \times 10^{4}\,NC ^{-1}$. The distance ' $d$ ' between the point charges $A$ and $B$ is..............$m$

A charged water drop whose radius is $0.1\,\mu m$ is in equilibrium in an electric field. If charge on it is equal to charge of an electron, then intensity of electric field will be.......$N/C$ $(g = 10\,m{s^{ - 1}})$