Hello Everyone, Am Manjeet Singh and Today we will Discuss about Dipole Moment And Dipole Field... So Let's Start...
Dipole Moment: Dipole Moment (p) is a measure of the strength of electric dipole. It is a vector quantity whose magnitude is equal to protect of the magnitude of either charge and the distance between them.
i.e. p=q(2a) or |p|=q(2a)
By convention, the direction of p is from negative to positive charge.
Then SI unit of dipole moment is coulomb-metre (C-m)
If charge q gets larger, and the distance 2a gets smaller and smaller, keeping the product |p|=q×2a=constant, we get what is called an ideal dipole or point dipole. Thus, an ideal dipole is the smallest dipole having almost no size.
Physical Significance of electric dipoles...
The study of electric dipoles is important for electrical phenomena in matter. Matter, as we know, consists of atoms or molecules which are electrically neutral. In a molecule, there are positively charged nuclei and negatively charged electrons. If the centre of mass of positive charges coincides with the centre of mass of negative charges, the molecule behaves as a non-polar molecule. On the contrary, if the centre of mass of positive charges does not coincide with the centre of mass of negative charges, the molecule behaves as a polar molecule and it possesses some intrinsic or permanent dipole moment. In the absence of an external electric field, the dipole moments of different molecules in a piece of matter are randomly oriented, so that net dipole moment of the piece is zero. When an external electric field is applied, the polar molecules tend to align themselves along the field and some net dipole moment developes. The piece of matter is said to have been polarised.
When non-polar molecules are subjected to the action of an external electric field, the centres of mass of positive and negative charges in the molecule get displaced in opposite directions. Thus, the external field induces some dipole moment in the molecule in the direction of the field. The induced dipole moments of different molecules in the sample add up vectorially to produce some net total dipole moment.
Dipole Field: The Dipole field is the electric field produced by an electric dipole. It is the space around the dipole in which the electric effect of the dipole can be experienced. The electric field of the pair of charge (-q and +q) at any point in space can be found from Coulomb's law and the superposition principal. To calculate dipole field intensity at any point, we imagine a unit positive charge held at that point. We calculate force on this charge due to each charge of the dipole and take vector sum of the two forces. This gives us dipole field intensity at that point. We shall show that though the total charge of electric dipole is zero, the field of the electric dipole is not zero. This is because the charge q and -q are separated by some distance. The electric fields due to these charges, when added, do not cancel out. However, at distances much larger than the separation of two charges, i.e., r>>2a, the fields due to q and -q largely cancel out. Therefore, at large distances from the dipole, the dipole field falls off more rapidly than like E~1/r² for a point charge.
If you satisfied with this information then like, comment and share this article with your friends. Thanks...
Created By Manjeet Singh...
Dipole Moment: Dipole Moment (p) is a measure of the strength of electric dipole. It is a vector quantity whose magnitude is equal to protect of the magnitude of either charge and the distance between them.
i.e. p=q(2a) or |p|=q(2a)
By convention, the direction of p is from negative to positive charge.
Then SI unit of dipole moment is coulomb-metre (C-m)
If charge q gets larger, and the distance 2a gets smaller and smaller, keeping the product |p|=q×2a=constant, we get what is called an ideal dipole or point dipole. Thus, an ideal dipole is the smallest dipole having almost no size.
Physical Significance of electric dipoles...
The study of electric dipoles is important for electrical phenomena in matter. Matter, as we know, consists of atoms or molecules which are electrically neutral. In a molecule, there are positively charged nuclei and negatively charged electrons. If the centre of mass of positive charges coincides with the centre of mass of negative charges, the molecule behaves as a non-polar molecule. On the contrary, if the centre of mass of positive charges does not coincide with the centre of mass of negative charges, the molecule behaves as a polar molecule and it possesses some intrinsic or permanent dipole moment. In the absence of an external electric field, the dipole moments of different molecules in a piece of matter are randomly oriented, so that net dipole moment of the piece is zero. When an external electric field is applied, the polar molecules tend to align themselves along the field and some net dipole moment developes. The piece of matter is said to have been polarised.
When non-polar molecules are subjected to the action of an external electric field, the centres of mass of positive and negative charges in the molecule get displaced in opposite directions. Thus, the external field induces some dipole moment in the molecule in the direction of the field. The induced dipole moments of different molecules in the sample add up vectorially to produce some net total dipole moment.
Dipole Field: The Dipole field is the electric field produced by an electric dipole. It is the space around the dipole in which the electric effect of the dipole can be experienced. The electric field of the pair of charge (-q and +q) at any point in space can be found from Coulomb's law and the superposition principal. To calculate dipole field intensity at any point, we imagine a unit positive charge held at that point. We calculate force on this charge due to each charge of the dipole and take vector sum of the two forces. This gives us dipole field intensity at that point. We shall show that though the total charge of electric dipole is zero, the field of the electric dipole is not zero. This is because the charge q and -q are separated by some distance. The electric fields due to these charges, when added, do not cancel out. However, at distances much larger than the separation of two charges, i.e., r>>2a, the fields due to q and -q largely cancel out. Therefore, at large distances from the dipole, the dipole field falls off more rapidly than like E~1/r² for a point charge.
If you satisfied with this information then like, comment and share this article with your friends. Thanks...
Created By Manjeet Singh...
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