Electrostatics Flashcards
Electric charge
Bodies with electric charge exert force on each other. This is electric interaction.
Si unit of charge (q)
Coloumb (c)
Can electric charge exist on its own?
No
Cation
Positive ion
Anion
Negative ion
Charges create this around them selves and they exert force on each other through this.
Force field
Structure of force field
Field lines
Direction of field line gives…
… direction of force acting on a positive test charge
Density of field lines gives the?
Magnitude of force
What is true for a homogeneous electric field?
- force acting on a positive test charge has the same strength
- force has the same direction at each point
- field lines are parallel
- density of field lines are uniform
Electric field between the plates of a capacitor is..
Homogeneous
Electric dipole
Two charges of equal magnitude but opposite signs at a given distance (d). Electric field is Inhomogeneous. Strength of a dipole is given by the electric dipole moment (p)
Definition of voltage (U)
The work needed to move a unit charge
The voltage between two points equals..
The difference between their electric potentials
Equipotential surface
The set of all points which have the same electric potential value.
What is a capacitor?
An electrical component that is capable of storing electric charge and energy as well as creating homogenous electric field. Simplest form is the parallel plate capacitor.
The cell membrane resembles a..
Capacitor
The greater charge of the capacitor plates..
The greater the electric field strength as well as the voltage between them
Capacitance
The electric charge of a capacitor divided by its voltage
The capacitance is a measure for..
The charge-storing ability of a capacitor which gives the charge stored in a capacitor if its voltage is 1 V.
The greater the surface area of the plates, the stronger the fields and more charge required to maintain a given voltage.
The electric energy stored in the capacitor.
The work (We) needed to charge the capacitor which is stored as energy in the electric field of the capacitor. The more more charge is transferred to the plates of the capacitor, the stronger the electric field and the greater the energy.
