Four charges are placed at the circumference of a dial clock as shown in figure. If the clock has only hour hand, then the resultant force on a charge $q_0$ placed at the centre, points in the direction which shows the time as

Figures below show regular hexagons, with charges at the vertices, In which of the following cases the electric field at the centre is not zero.

$A$ and $C$ are concentric conducting spherical shells of radius $a$ and $c$ respectively. $A$ is surrounded by a concentric dielectric radius $a$ , outer radius $b$ and dielectric constant $k$ . If sphere $A$ be given a charges $Q$ , the potential at the outer surface of the dielectric is 

Two charges  $ + 3.2\, \times \,{10^{ – 19}}\,C$ and $ – 3.2\, \times \,{10^{ – 19}}\,C$ kept $2.4\,\mathop A\limits^o $ apart forms a dipole. If it is kept in uniform electric field of intensity $4\, \times \,{10^{5\,}}\,volt/m$ then what will be its potential energy in stable equilibrium

A point charge $'q'$ is placed at a point inside a hollow conducting sphere. Which of the  following electric force pattern is correct ?