Update cheatsheet.en.md

12.temporary_ins/90.electromagnetism-in-vacuum/10.maxwell-equations/20.overview/cheatsheet.en.md

@@ -456,7 +456,7 @@ I recognize here the law of conservation of charge.
   $`\text{div}\,\overrightarrow{j} +\dfrac{\partial \dens^{3D}}{\partial t}=0`$
 --------------------->
 
-* We can *integrate this local equality* over any volume $`\tau`$:
+* We can *integrate this local equality* over any volume $`\tau`$ :   
   <br>
   $`\displaystyle\iiint_{\tau} \Big(\text{div}\,\overrightarrow{j} +\dfrac{\partial \dens}{\partial t}\big)\,d\tau=0`$     
   <br>
@@ -469,16 +469,16 @@ I recognize here the law of conservation of charge.
   <br>
   *Applied to the first term* of the equality, we obtain :   
   <br>
-  **$`\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} + \iiint_{\tau}\dfrac{\partial \dens}{\partial t}\,d\tau=0`$** .
+  **$`\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} + \iiint_{\tau}\dfrac{\partial \dens}{\partial t}\,d\tau=0`$**.   
 
-* Noting again that *space and time are independent in classical physics*, the order of derivation or integration with respect to a spatial variable and a time variable does not matter:
+* Noting again that *space and time are independent in classical physics*, the order of derivation or integration with respect to a spatial variable and a time variable does not matter :   
   <br>
-  **$`\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} +\dfrac{\partial}{\partial t} \left(\iiint_{\tau}\dens \,d\tau\right)=0`** .
+  **$`\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} +\dfrac{\partial}{\partial t} \left(\iiint_{\tau}\dens \,d\tau\right)=0`$**.   
 
-* Noting that *$`\displaystyle\iiint_{\tau}\dens^{3D} \,d\tau`$ is the total charge $`Q_{int}`*
-  contained in the volume $`\tau`$, we obtain the **integral expression of the conservation law** of charge:
+* Noting that *$`\displaystyle\iiint_{\tau}\dens^{3D} \,d\tau`$ is the total charge $`Q_{int}`$*
+  contained in the volume $`\tau`$, we obtain the **integral expression of the conservation law** of charge :   
   <br>
-  **$`\mathbf{\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} +\dfrac{dQ_{int}}{dt}=0}`** .
+  **$`\mathbf{\displaystyle\oiint_S \overrightarrow{j}\cdot \overrightarrow{dS} +\dfrac{dQ_{int}}{dt}=0}`$**.   
 
 <br>
 
@@ -493,15 +493,15 @@ I recognize here the law of conservation of charge.
 * The **sensitivity** of a particle **to electromagnetic interaction** is quantified
   by the parameter called *electric charge* of the particle.
 
-* The force that describes the *action of an electromagnetic field $`\big(\overrightarrow{E}, \overrightarrow{B}\big)`*
-  on a particle with charge $`q`$ is the **Lorentz force**, with the expression:
+* The force that describes the *action of an electromagnetic field $`\big(\overrightarrow{E}, \overrightarrow{B}\big)`$*
+  on a particle with charge $`q`$ is the **Lorentz force**, with the expression :   
   <br>
   **$`\overrightarrow{F}_{Lorentz}=q\Big(\overrightarrow{E}+\overrightarrow{v}\times\overrightarrow{B}\Big)`$**
   <br>
   &nbsp;&nbsp;where $`\overrightarrow{v}`$ is the velocity vector of the particle in the inertial frame of the observer.   
 
-* *During an elementary displacement $`\overrightarrow{dl}`* of the particle in the electromagnetic field
-  $`\big(\overrightarrow{E}, \overrightarrow{B}\big)`*, the **work of the Lorentz force** is written as:
+* *During an elementary displacement $`\overrightarrow{dl}`$* of the particle in the electromagnetic field
+  $`\big(\overrightarrow{E}, \overrightarrow{B}\big)`$*, the **work of the Lorentz force** is written as :   
   <br>
   **$`d\mathcal{W}_{Lorentz}=\overrightarrow{F}_{Lorentz}\cdot\overrightarrow{dl}`**,   
   <br>
@@ -517,8 +517,8 @@ I recognize here the law of conservation of charge.
   <br>
   where $`\Big(\overrightarrow{v},\overrightarrow{B},\overrightarrow{dl}\Big)`$ is the scalar triple product of the sequence of the three vectors.   
 
-* Since the *vectors $`\overrightarrow{v}`$ and $`\overrightarrow{dl}=\overrightarrow{v}\,dt`* are *collinear*, the scalar triple product
-  is zero:
+* Since the *vectors $`\overrightarrow{v}`$ and $`\overrightarrow{dl}=\overrightarrow{v}\,dt`$* are *collinear*, the scalar triple product
+  is zero :   
   <br>
   *$`\Big(\overrightarrow{v},\overrightarrow{B},\overrightarrow{dl}\Big)=0`$*,