Electric Fields Flashcards
Electro(magnetic) forces arise from …
electric charges
Is the electrostatic force attractive/Repulsive/both?
Both attractive and repulsive
The electric field has a unique ..
value at every point in space
What is an electric field?
It has the magnitude and direction of the electric force acting on a positive unit charge.
What are electric field lines?
Lines which are everywhere tangent to the electric field direction.
Where are electric field lines denser?
Where the electrostatic field is higher
What is the strength of the field proportional to?
The density of field lines
What constitutes an ‘electric dipole’?
Two equal and opposite charges close together
Where are Dipolar interactions important?
At molecular level or in dielectrics
For any path from A to B in a static electric field what is the work done?
The work done is independent of the path taken.
What is electric potential?
The work necessary to move a unit charge between two points in a electric field.
What does electric potential have to be calculated relative to?
An established origin
In terms of voltage what way do electric field lines run?
From positions of higher voltage to lower voltage.
Electric field produce forces on charges what can these forces be used for?
To manipulate the motion of the charges
What are examples of electric fields being used to manipulate the motion of charges?
Motion between cathode and anode (TV tube ,X-ray tube)
