When a test charge is brought in from infinity along the perpendicular bisector of an electric dipole,the work done is ..........

There exists a non-uniform electric field along the $x-$ axis as shown in the figure below. The field increases at a uniform rate along the $+ve$ $x-$ axis. $A$ dipole is placed inside the field as shown. Which one of the following is correct for the dipole?

Six charges are placed at the vertices of a regular hexagon as shown in the figure. The electric field on the line passing through point $O$ and perpendicular to the plane of the figure at a distance of $x (>> a)$ from $O$ is

The angle between the dipole moment and electric field at any point on the equatorial plane is (in $^{\circ}$)

The distance between charges $+q$ and $-q$ is $2l$ and between $+2q$ and $-2q$ is $4l$. The electrostatic potential at point $P$ at a distance $r$ from centre $O$ is $-\alpha \left[ \frac{ql}{r^2} \right] \times 10^9 \text{ V}$,where the value of $\alpha$ is . . . . . . . (Use $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9 \text{ Nm}^2\text{C}^{-2}$)

An electric dipole consists of two equal and opposite charges of $2 \ \mu C$ separated by a distance of $3 \ cm$. If it is placed in an external electric field of $2 \times 10^{5} \ N/C$,the maximum torque experienced by it is: