6.2 Electric Fields Flashcards
Define electric field strength
The force experienced per unit positive charge at that point
What direction do electric fields travel
The direction in which a positive charge would love when placed at that point
Positive to negative
Name one natural electric field
Lightning
How can you create a simple electric field
Rub a glass rod with a silk cloth
Electrons travel from rod to cloth
Rod becomes positively charged and cloth becomes negatively charged
Place the rod near an open tap and observe the water bending towards it
What is coloumbs law
Any two point charges that exert an electrostatic force on each other is directly proportional to the product of their charges and inversely proportional to the square of the distance between them
How can you investigate the forces between two charged metal spheres
-Cover 2 balls in conductive paint
-Balls can be positively charged by touching each momentarily to the positive electrode of a high tension supply
-Lower one ball towards the other which is on a mass balance and the reading will increase
What are some similarities and differences between electric field of a point charge and magnetic field of a point mass
S:
Both point masses and point charges produce radial fields
Force inversely proportional to separation squared
D:
Mass always produces an attractive field whereas charges produced attractive and repulsive fields
What does a uniform electric field mean
The direction and strength of the force is the same everywhere in the electric field
How can you produce an uniform electric field
Oppositely charged parallel plates
What does the capacitance of an electric field depend on
Area of overlap between plates
Separation
Dielectric used between plates
Define electric potential
Work done per unit charge in bringing a positive charge from infinity to a point
Define electric potential energy
Work done to move a positive charge from infinity to a point
