Consider the following statements about electric dipole and select the correct ones S1 : Electric dipole moment vector $\overrightarrow{p}$ is directed from the negative charge to the positive charge S2 : The electric field of a dipole at a point with position vector $\overrightarrow{r}$ depends on $|\overrightarrow{r}|$ as well as the angle between $\overrightarrow{r}$ and $\overrightarrow{p}$ S3 : The electric dipole potential falls off as $\frac{1}{r^{2}}$ and not as $\frac{1}{r}$ S4 : In a uniform electric field, the electric dipole experiences no net forces but a torque $\overrightarrow{ au} = \overrightarrow{p} imes \overrightarrow{E}$

Question

Consider the following statements about electric dipole and select the correct ones S1 : Electric dipole moment vector $\overrightarrow{p}$ is directed from the negative charge to the positive charge S2 : The electric field of a dipole at a point with position vector $\overrightarrow{r}$ depends on $|\overrightarrow{r}|$ as well as the angle between $\overrightarrow{r}$ and $\overrightarrow{p}$ S3 : The electric dipole potential falls off as $\frac{1}{r^{2}}$ and not as $\frac{1}{r}$ S4 : In a uniform electric field, the electric dipole experiences no net forces but a torque $\overrightarrow{	au} = \overrightarrow{p} 	imes \overrightarrow{E}$

Dr. Abubacker · Accepted Answer

(d) An electric dipole is a pair of equal and opposite charges $q$ and $- q$ separated by some distance $2a.$ Its dipole moment vector $\overrightarrow{p}$ has magnitude $2qa\ $and is in the direction of the dipole axis from $- q$ to $q$
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The electric field due to a dipole at a point $p$ is
$E = \frac{p}{4\pi\varepsilon_{0}}\frac{\sqrt{3\cos^{2}{	heta + 1}}}{r^{3}}(r > > a)$
The electric dipole potential falls off at large distance, as $\frac{1}{r^{2}}$ not as $\frac{1}{r}$, characteristic of the potential due to a single charge.
In a uniform electric field $\overrightarrow{E},$ a dipole experiences a torque $\overrightarrow{	au}$ given by $\overrightarrow{	au} = \overrightarrow{p} 	imes \overrightarrow{E}$ but experiences no net force

Explanation

Reviewed by Dr. Abubacker

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