# What properties define a negative charge

## Charges & electric field

The electric field strength \ (\ vec E \) is the measure of the strength and direction of an electric field, i.e. the ability of a charge to exert force on other charges.

The electric field strength \ (\ vec E \) is defined as the quotient of the electric force \ ({\ vec F _ {\ rm {el}}} \) on a test charge and the charge \ (q \) of the test charge: \ [\ vec E = \ frac {{{{\ vec F} _ {\ rm {el}}}}} {q} \ quad (1) \]

 size Surname symbol definition electric field strength \ (\ vec E \) \ (\ vec E = \ frac {\ vec F _ {\ rm {el}}} {q} \) unit Surname symbol - \ (\ frac {\ rm {N}} {\ rm {C}} \) or \ (\ frac {\ rm {V}} {\ rm {m}} \)

The electric field strength \ (\ vec E \) always shows in the direction of the electric force on positive charges.

Equation \ ((1) \) gives an explanation of what you can imagine by an electric field strength of \ (1 \, \ frac {\ rm {N}} {\ rm {C}} \): An electric field has at a point in space the strength \ (1 \, \ frac {\ rm {N}} {\ rm {C}} \), if a charge of the size \ (1 \, \ rm {C} \) there has a force of \ (1 \, \ rm {N} \) learns.

If one wants to express in short form that the unit of the electric field strength is \ (1 \, \ frac {\ rm {N}} {\ rm {C}} \), one can write \ ([E] = 1 \, \ frac {\ rm {N}} {\ rm {C}} \).