3.5 Electricity Flashcards
Charge carriers
Charged particles that move through substance when PD applied across it
Kirchoff’s 1st Law
Current passing through 2 or more components in series is the same through each component -> At a junction the total current in = total current out
Kirchoff’s 2 Law
2 or more components in series - total PD across all the components is = to sum of the PD’s across each component -> Sum of emf’s around complete loop = sum of PD’s around the loop
Critical temperature
Temperature at or below which a superconducting material has zero resistivity
electrolysis
process of electrical conduction in a solution or molten substance due to charged ions moving to oppositely charged electrode
electrolyte
solution that conducts electricity
emf
electrical energy per unit charge produced inside electrical source
electron volt
work done when an electron is moved through a PD of 1V
internal resistance
resistance inside the source of electrical energy - loss of PD per unit current in the source when current passes through it
light-dependent resistor
resistance decreases in light
negative temperature coefficient
resistance of a semiconductor decreases when its temperature is increased
Ohm’s Law
PD across a metallic conductor is proportional to the current - if physical conditions remain constant
positive temperature coefficient
resistance of material increases when its temperature is increased
potential difference
work done per unit charge between 2 points when charge moves from one to the other
potential divider
2 or more resistors in series connected to a source of pd
potential energy
energy of an object due to its position
power
rate of energy transfer
resistance
V/I
resistivity
resistance per unit length x area of cross section
semiconductor
substance in which the number of charge carrier increases as the temperature increases
sensitivity of an instrument
output reading per unit input
specific charge
charge to mass ratio
supercondctor
material that has zero electrical resistance
terminal pd
pd across the terminals of a power supply
terminal speed
maximum speed reached by an object when the drag force is equal and opposite to the force causing the motion
thermistor
resistor which is designed to have a resistance that changes with temperature
Fleming’s Left hand rule
rule relating the force, magnetic field and current all acting at right angles to eachother on a current carrying conductor in a magnetic field
Fleming’s Right hand rule
rule relating force, magnetic field and current of a conductor when it cuts across magnetic field and an emf is induced in it
