Скачать или смотреть Electric field Mdcat /Ecat Lecture 02 by doctor of science

Assamaalikum this lecture is for all board Mdcat and Ecat


An *electric field* is a fundamental concept in electromagnetism that describes the influence exerted by electric charges on other charges in their vicinity. It is a vector field, meaning it has both *magnitude* (strength) and *direction* at every point in space.

*Key Properties of an Electric Field:*
1. *Definition:*
The electric field (**E**) at a point is defined as the *electric force (F)* experienced by a small *positive test charge (q)* placed at that point, divided by the magnitude of the test charge:
\[
\mathbf{E} = \frac{\mathbf{F}}{q}
\]
Unit: *Newtons per Coulomb (N/C)* or **Volts per meter (V/m)**.

2. *Direction:*
The electric field points *away from positive charges* (since a positive test charge would be repelled).
It points *toward negative charges* (since a positive test charge would be attracted).

3. *Sources of Electric Field:*
*Stationary charges* (electrostatics) produce electric fields.
*Time-varying magnetic fields* (Faraday's Law) can also induce electric fields.

4. *Field Lines (Visualization):*
Electric field lines represent the direction and strength of the field.
*Denser lines* indicate a **stronger field**.
Lines *never cross* (since the field has a unique direction at each point).
Lines *start on positive charges* and **end on negative charges**.

5. *Mathematical Representation:*
For a *point charge (Q)**, the electric field at distance **r* is given by Coulomb's Law:
\[
\mathbf{E} = k \frac{Q}{r^2} \hat{r}
\]
where \( k = \frac{