Chapter 16 - charge and field Flashcards
What is an electric field?
A region around a charged object in which other charges can be attracted or repelled
What is the symbol for electric charge?
Q
What are the units of electric charge?
Coulombs, C
What is Coulomb’s law?
F = KQ1Q2/r^2
What is the equation used to find the force if attraction or repulsion between two charged particles?
Coulomb’s law
F = KQ1Q2/r^2
What is K?
1/4πε0
What is ε?
The permittivity of the material between two charges?
What is ε0?
The permittivity of free space (used for air between two charges)
8.85x10^-12
What are the units of the permittivity of free space?
C^2N-1m^-2
What is the electric field strength?
The force a positive test charge of 1C would experience at that point in the field
Are attractive forces positive or negative?
negative
Are repulsive forces positive or negative?
positive
What is the symbol for electric field strength?
E
Is electric field strength a vector or a scalar quantity?
vector
What are the units of electric field strength?
NC^-1
What kind of field does a point charge(or body that behaves as if charge is concentrated at the centre) have?
Radial field
What is the formula for electric field strength?
E = F/Q
In a radial electric field, what is the inverse square law for electric field strength?
E ∝ 1/r^2
What is the formula for electric field strength around a point charge?
E = KQ/r^2
In what directions do field lines/lines of force point for an electric field?
The direction in which a positive test charge would experience a force if it were in the field
How do field lines/lines of force show a stronger electric field?
Lines are closer together where the filed is stronger
How do field lines/lines of force show a uniform electric field?
They are equally spaced and parallel to each other
How can electric potential, V, be found graphically?
The area under an E/r graph
What kind of energy does a charge in an electric field have?
Electrical potential energy