Physics-electricity
Charge flow (coulumbs, C) = current (Amps, A) x time (seconds, s)
Q = I x t
Ohms law
Potential difference is proportional to current
Ohms laws experiment conclusion- As the potential difference increases, so does the current
Potential difference (V) = current (A) x resistance (ohms- horse shoe)
Rules for series and parallel circuits
Series- connected in 1 loop
-Everywhere in the series circuit, the current is the same
-In series circuit, potential difference is shared between the components
Parallel- Different branches
-Everywhere in a parallel circuit, potential difference is the same (on each branch)
-The current is shared between the components
AC & DC currents
-Potential difference makes current flow through resistors
-High resistor, more energy needed
-Current takes path with less/ low resistance
To not get shocked:
Difference in voltage causes electricity to pass from one to another.
Humans are at 0V. So if we were to touch live wire, we would get an electric shock because of large current.
raise potential difference to be the same as electricity- no current
Plugs
3 types of wires:
-Neutral (blue)- completes the circuit and carries current away. it has 0V
-Earth wire (green + yellow)- Stops appliance casing from becoming live. Provides an alternative pathway, takes the current to flow away, rather than to us. Is normaly at 0V
-If live wire came loose and touched the casing, electric shock.
-Live (brown)- Provides the alternating potential difference from the main supply. Normally at 230V
types of energy stores:
-kinetic
-electrostatic
-gravitational potential
-thermal
-magnetic
-elastic
-nuclear
-chemical
Energy tranferred (J) = Power (W) x time (s)
Power = potential difference x current
Energy = voltage x charge
Charge- a measure of the total current that flowed within a certain period of time
-if any components are disconnected, the whole circuit will stop working
Current = total potential difference / total resistance
I = V/R (rearranged form of ohms law)
components with greater resistnace will always have a higher share of voltage ( more force needed to push charge through areas of higher resistance)
more than 1 loop- more useful than series because as each component has its own loop, if any other components break, the overall circuit is still intact
Vtotal (potential difference) = V1 = V2 = V3...
Itotal (current) = I1 + I2 +I3 ....
loop with greater resistance, have a lower share of current becuase more energy is needed to pass resistor
More components in circuit = lower total resistace
Alternative current (AC)
-The current changes directions
-Current is not constant
Direct current (DC)
Charge is always flowing in the same direction
Either positive or negative
Charge fluctuates between postive and negative