The angle between the electric dipole moment of a dipole and the electric field strength due to it on the equatorial line is (in $^{\circ}$)

Two charges of $+25 \times 10^{-9} \, C$ and $-25 \times 10^{-9} \, C$ are placed $6 \, m$ apart. Find the ratio of the electric field intensity at a point $4 \, m$ from the center of the electric dipole on the $(i)$ axial line and $(ii)$ equatorial line.

An electric dipole with dipole moment $p$ is placed with its axis at $30^{\circ}$ to a uniform electric field. The work done in rotating the dipole to a position where its axis is perpendicular to the field is

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

Two charged particles each of mass $9.8 \text{ g}$ and charges $+20 \mu\text{C}$ and $-20 \mu\text{C}$ are attached to the two ends of a massless and rigid uniform non-conducting rod of length $50 \text{ cm}$. This arrangement is held in a uniform electric field of $12.1 \text{ N/C}$,such that the rod makes a very small angle with the field direction. If the rod is set free,the minimum time needed for the rod to become parallel to the direction of the electric field is ................ seconds.

Electric charges $q, q, -2q$ are placed at the corners of an equilateral triangle $ABC$ of side $l$. The magnitude of the electric dipole moment of the system is