$A$ dipole is placed in a uniform electric field,its potential energy will be minimum when the angle between its axis and field is

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 point charges $-q$ and $+q$ are placed at a distance of $L$,as shown in the figure. The magnitude of electric field intensity at a distance $R$ $(R \gg L)$ varies as:

Three point charges $q, -2q$ and $q$ are placed along the $x$-axis at $x = -a, 0$ and $a$ respectively. As $a \rightarrow 0$ and $q \rightarrow \infty$ while $qa^2 = Q$ remains finite, the electric field at a point $P$, at a distance $x$ $(x \gg a)$ from $x = 0$ is $E = \frac{\alpha Q}{4 \pi \epsilon_0 x^\beta} \hat{i}$. Then:

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:

Five identical small electric dipoles are placed at a distance $r$ from an infinitely long straight wire carrying a uniform charge density $\lambda$. If they experience forces of magnitude $F_1, F_2, F_3, F_4$ and $F_5$ respectively,then: