Electricity Flashcards
insulator
an object that does not readily conduct heat or electricity
charging of insulators
friction- when 2 insulators are rubbed together one of the materials gains electrons (becomes +tive charge) and the other loses electrons (becomes -tive charge)
objects of the same charge repel
objects of opposite charges attract
uses of electrostatics
paint spraying
dust extraction
dangers of electrostatics
objects can become earthed- dangerous build up of static charge which can cause sparks
formula for current
charge (Q)/ time (T)
define current
the RATE of flow of charge- charge carriers are generally electrons, measured in amps (A)
define coulomb
amount of charge that passes in 1 second when the current = 1A
define potential difference
the energy converted per unit charge moved (out circuit) measured in volts (V)
formula for voltage
energy (W) /charge(Q)
define resistance
how difficult it is for current to flow through a component, measured in ohms
what is resistance dependent on
length of wire- longer wire = higher resistance
cross sectional area of wire- wider wire= lower resistance
resistivity of wire - dependent on material, wire structure, environmental factors e.g temp
series circuit
circuit where the current follows one path
parallel circuit
circuit where current splits in more than 2 paths
current, voltage and resistance rules
for series: Rt=R1+R2 I1=I2=I3 Voltage splits but is dependent on the components for parallel: v1=v2=v3 current splits but depends on components total resistance is less than the branch w/ smallest resistance
formula for power
currentxvoltage
