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Electric Charges and Fields — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields2 Marks
Question
Explain electric field produced by the point electric charge.
✓

Answer

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►Let us consider a point charge $Q$ placed in vacuum, at the origin $O$. If we place another point charge q at a point P , where $\overrightarrow{ OP }=\vec{r}$, then the charge $Q$ will exert a force on $q$ as per Coulomb's law.
►The external effect which produces force on charge q , is called electric field of charge $Q$.
►Electric field at point ' P '
$\overrightarrow{ E }(r)=\frac{1}{4 \pi \varepsilon_0} \cdot \frac{ Q }{r^2} \cdot \hat{r}$
Where $\hat{r}$ is the unit vector in the direction of electric field.
►The area around any electric charge or electric charge system where its effect prevails is called the electric field of the electric charge or electric charge system.
OR
►"In the region of an electric charge, or a system of charge, the electrostatic force acting on a unit positive charge placed at some point is called
the electric field of the given electric charge / system of charges."
►Electric field is a vector quantity.
►Its unit is $N / C$ or $V / m .\left( M ^1 L^1 T^{-3} A^{-1}\right)$

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