An electric dipole of dipole moment $p$ is aligned parallel to a uniform electric field $E$. The energy required to rotate the dipole by $90^{\circ}$ is $\left[\begin{array}{ll}\sin 0^{\circ}=0, & \sin 90^{\circ}=1 \\ \cos 0^{\circ}=1, & \cos 90^{\circ}=0\end{array}\right]$

If the magnitude of the intensity of the electric field at a distance $x$ on the axial line and at a distance $y$ on the equatorial line for a given electric dipole are equal,then the ratio $x:y$ is:

Point $P$ lies on the axis of a dipole. If the dipole is rotated by $90^o$ anticlockwise,the electric field vector $\vec{E}$ at $P$ will rotate by

The electric field due to an electric dipole at a distance $r$ from its centre in the axial position is $E$. If the dipole is rotated through an angle of $90^{\circ}$ about its perpendicular axis,the electric field at the same point will be

Two short dipoles $A$ and $B$, $A$ having charges $\pm 2 \mu C$ and length $1 \text{ cm}$, and $B$ having charges $\pm 4 \mu C$ and length $1 \text{ cm}$, are placed with their centres $80 \text{ cm}$ apart as shown in the figure. The electric field at a point $P$, equidistant from the centres of both dipoles, is . . . . . . $\text{N/C}$.

Two charges $+q$ and $-q$ are placed at a distance $b$ apart as shown in the figure. The electric field at a point $P$ on the perpendicular bisector as shown is