electricity Flashcards
what is the definition of current
the rate of flow of charge
what is the equation for current
I=Q/T
what does I stand for
current
what does Q stand for
charge
what does T stand for
temperature
why are metals amazing conductors
they consist of metal ions which pass the charge around like a normal solid ,however, on top of this they have delocalised electrons which roam free throughout the metal and can pass the charge on faster by colliding with other delocalised electrons or ions throughout the cell
how does current work in a series circuit
it is the same throughout the series circuit at any point in the series circuit
It=I1=I2=I3
what do resistors do in a circuit
they reduce the current in the circuit
how does current work in a parallel circuit
All the different branches add up to the total current in the circuit
It=I1+I2+I3 e.t.c
Why do some branches have more current flowing through them as oppose to others from time to time
the current will always choose the path of least resistance so if there’s a resistor on one branch and there isn’t a resistor on another it is likely to have more resistance than the other so less current will flow through that one
how is resistance effected with the addition of new branches
the overall resistance of the circuit decreases as more branches are added
how do you measure current
using an ammeter(the unit is in amps)
how do you measure charge
using a coulombmeter (the unit is in C)
how do you measure voltage
using a voltmeter(the unit is in V)
what is the definition of voltage
the energy transferred per unit charge
what is the equation for voltage
Voltage=energy/charge V=E/Q
what is the relationship of voltage in series circuits
Vt=V1+V2+V3
what is the relationship of voltage in parallel circuits
Vt=V1=V2=V3
what is the relationship of resistance in series circuit
Rt=R1+R2+R3
definition of electrical resistance
the ratio between the voltage across a component and the current passing through it
equation for resistance
resistance=voltage/current R=V/I
what is the relationship for resistance in parallel circuits(extension)
1/Rt=1/R1+1/R2+1/R3 e.t.c
what is the relationship between resistance in a constantan wire and the length of it
resistance in a constantan wire is directly proportional to its length
for a fixed resistor what is the voltage and current situation
voltage and current are directly proportional in a fixed resistor
what is an ohmic component
the current and voltage are directly proportional
what is the function of a diode
only lets the current pass in one direction
what is a light dependant resistor (LDR)
it is a resistor in which varies based on the light intensity. The higher the light intensity, the lower the resistance
what is a thermistor
a resistor which varies based on the heat intensity. The higher the heat intensity the lower the resistance
what is the relationship between resistance and temperature
R is inversely proportional to T
