Physics Flashcards
(97 cards)
charged particle
a particle with an electric charge e.g. ion, electron, proton
unit of elementary electrical charge
coulomb
conductors
the materials electricity (electrons) can flow through. e.g. copper, silver, gold, graphite, salt
insulators
the materials electricity (electrons) cannot flow through = static
static electricity
when two non-metal insulators are rubbed together, the friction allows electrons to be removed from one of the objects to the other, where they build up because the electrons don’t flow like in insulators.
static electricity is
potential energy. it does not move. it is stored.
charge in static electricity
one object becomes negatively charged, and the other becomes positively charged
static discharge
occurs when there is a loss of static electricity due to friction, conduction, or induction.
conduction
direct contact
induction
through an electric field (no direct contact)
voltage
the difference in potential energy across an energy source or circuit component. also called the potential difference.
unit for voltage
volts = V
current
the rate of coulombs flowing in the circuit. current is the number of coulombs per second
unit for current
amperes (amps) = A. 1A = 1 coulomb per second
current is
kinetic energy
direct current (DC)
electrons flow in the same direction in a wire
alternating current (AC)
electrons flow in different directions in a wire
resistance
when it is difficult for a current to flow through a circuit component. opposes the flow of current through a circuit component.
unit for resistance
ohm (Ω)
the effect longer wires have on resistance
increased resistance as the electrons travel further and lose energy
the effect wider wires have on resistance
decreased resistance as more electrons fit in a wide wire = less lost energy
voltage drop
a loss of potential energy when current flows through a circuit component. this is due to the transfer of electrical energy to other forms - light, sound, heat etc.
series circuit
when all the circuit components are in a line. the circuit forms a single loop.
current in a series circuit
the same current flows through every circuit component. the current measured at any point of the circuit will be the same value.