Definition of the Electric Field

The Electric Field Definition of the Electric Field Electric Field Due to a Point Charge Electric Field Due to Multiple Point Charges The Electric Dipole Homework

Definition of the Electric Field 


The electric field at a point in space is defined as the electric 
 force  acting on a test particle placed at the point divided by the charge  of the test particle: 







  

It is assumed that the test charge is small enough that it does not disturb the charge distribution responsible for the electric field.

Figure 19.10

Units and Direction of E The SI units of the electric field are newtons per coulomb (N/C) 


The direction of is the direction in which a positive test charge would be accelerated if placed in the field and released.

Electric Field Example 


A proton is placed in a uniform electric field . What must be the magnitude and direction of this field if the electrostatic force acting on the proton is to just balance its weight?

Electric Field Example 


A proton is placed in a uniform electric field . What must be the magnitude and direction of this field if the electrostatic force acting on the proton is to just balance its weight?      

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