Module 6 - Key Definitions Flashcards
What is a capacitor?
A capacitor is a circuit component that stores energy by separating charges onto two electrical conductors with an insulator between them.
What is capacitance?
Capacitance is an attribute of a capacitor that measures the quantity of charge which can be stored per unit potential difference across the plates of the capacitor.
What is a farad?
A farad is the unit of capacitance. One farad is equal to one coulomb per volt.
What is the definition of the time constant of a capacitor?
A capacitor’s time constant (τ) is the time taken for the charge remaining on a capacitor to decrease to 1/e of its initial value in seconds.
What is the definition of an electric field?
An electric field is the region around a body in which other charged bodies will feel a force due to the body’s electric charge.
In what direction to electric field lines point?
Electric field lines point in the direction a small positive charge would move if placed at that point.
What is the definition of electric field strength?
Electric field strength is the force (N) that one coulomb of charge (C) would experience (N C⁻¹).
What is the permittivity of a capacitor?
A capacitor’s permittivity is a constant related to the size of the capacitance (a bit vague but the permittivity is basically what dictates the capacitance).
What is the relative permittivity of a material?
The relative permittivity of a material is the factor by which ε₀ must be multiplied to obtain ε.
What is coulomb’s law?
Coulomb’s law states that the electrical force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them (description of F = Qq/kr² where k is constant).
What is the permittivity of free space (definition)?
ε₀ is the physical constant related to the size of the force between electrical charges in free space.
What is electric potential?
Electrical potential is the work done per unit positive charge to move that charge from infinity (where potential is zero) to a point in an electric field. Note that this is the same as electric potential energy per unit positive charge.
What is electric potential energy?
Electric potential energy is the work done to move that charge from infinity to a point in an electric field. Note that this is the same as electric potential, but not per positive charge.
What is a magnetic field?
A magnetic field is the region around a permanent magnet or a moving charge in which another body with magnetic properties will feel a force.
What is a solenoid?
A solenoid is a long coil of current-carrying wire.
