Current Potential difference
In a series circuit current is the The energy transferred per coulomb of charge moved
same everywhere between points
In a parallel circuit current is split o Electrons are given energy at / from the cell
into the different branches In a series circuit the p.d. across all the components
Current (A) = charge (C) add up to the p.d. across the cell/battery
o Its shared between the components in the
Time taken (s)
same ratio as their resistance
In a parallel circuit the p.d. of each branch is the same
P.d. (V) = energy transferred / work done (J)
Charge (C)
LDRs
As the light intensity increases
the resistance decreases at a
decreasing rate Resistance
LDRs are made up of
semiconductors so they conduct The ability of an electrical component to stop/resist
better under certain conditions the flow of the electric current
When light becomes more o The bigger the resistance, the smaller the
intense the number of free current for the same p.d.
charges in the conduction band In a series circuit Rtotal = R1 + R2 + ..
increases o By adding resistors there are more ions
which impedes the flow of electrons in the
circuit which means resistance increases
Thermistors In a parallel circuit the resistance
o By adding resistors in parallel there are
As temperature increases the alternate paths for the current to flow
resistance of a thermistor through which lowers resistance
decreases
o Hot = low resistance
o Cold = high resistance
Power equations
P
I² x R
In a series circuit current is the The energy transferred per coulomb of charge moved
same everywhere between points
In a parallel circuit current is split o Electrons are given energy at / from the cell
into the different branches In a series circuit the p.d. across all the components
Current (A) = charge (C) add up to the p.d. across the cell/battery
o Its shared between the components in the
Time taken (s)
same ratio as their resistance
In a parallel circuit the p.d. of each branch is the same
P.d. (V) = energy transferred / work done (J)
Charge (C)
LDRs
As the light intensity increases
the resistance decreases at a
decreasing rate Resistance
LDRs are made up of
semiconductors so they conduct The ability of an electrical component to stop/resist
better under certain conditions the flow of the electric current
When light becomes more o The bigger the resistance, the smaller the
intense the number of free current for the same p.d.
charges in the conduction band In a series circuit Rtotal = R1 + R2 + ..
increases o By adding resistors there are more ions
which impedes the flow of electrons in the
circuit which means resistance increases
Thermistors In a parallel circuit the resistance
o By adding resistors in parallel there are
As temperature increases the alternate paths for the current to flow
resistance of a thermistor through which lowers resistance
decreases
o Hot = low resistance
o Cold = high resistance
Power equations
P
I² x R
