Directions: (46-50) |
Polarisation of Dielectric |
When an insulator is placed in an external field, the dipoles become aligned. Induced surface charges on the insulator establish a poarization field \[{{\overrightarrow{E}}_{i}}\]in its interior. |
The net field \[\overrightarrow{E}\] in the insulator is the vector sum of \[{{\overrightarrow{E}}_{0}}\]and\[{{\overrightarrow{E}}_{i}}\], as shown in the figure. |
[a] |
[b] |
[c] |
On the application of external electric field, the effect of aligning the electric dipoles in the insulator is called polarisation and the field \[{{\overrightarrow{E}}_{i}}\], is known as the polarization field. The dipole moment per unit volume of the dielectric is known as polarization \[\left( \overrightarrow{P} \right)\]. |
For linear isotropic dielectrics, \[\overrightarrow{P}=\chi \overrightarrow{E}\], where 7 \[\chi =\]electrical susceptibility of the dielectric medium. |
A) \[{{O}_{2}}\]
B) \[{{H}_{2}}\]
C) \[{{N}_{2}}\]
D) \[HCl\]
Correct Answer: D
Solution :
In polar molecule the centres of positive and negative charges are separated even when there is no external field. Such molecule have a permanent dipole moment. Ionic molecule like HCl is an example of polar molecule.You need to login to perform this action.
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