kirchhoff's laws Flashcards
What is kirchhoffe’s first law
Sum of all current entering a junction is = sum of the currents leaving the junction
Is current throughout a SERIES circuit the same
yes, the current throughout the series circuit is the SAME.
ie. component A and Component B have the same current if in SERIES.
Is current throughout a PARALLEL circuit the same
NO, current is split when it enters the parallel circuit.
The total current in the parallel circuit must equal the current in the series circuit.
so if 1 component in the parallel circuit is = 0.2A , and the current in the series circuit is 0.5A, then it means the other component B in the parallel circuit = 0.3A in order to sum up to 0.5A
What is kirchhoffe´s second law
It states that in any complete loop around a circuit, the sum of PD of the cell or psu, must = the sum of all voltages of the components
eg. E = epsilon = pd of the cell
V1 = component a´s pd in series with V2 = component b´s pd
E = V1+V2
according to kirchhoffe´s 2nd law, what is the voltage of a component when it is in parallel with another component, and when it is in series with another component.
The voltage between 2 components in parallel is the SAME
The voltage between 2 components in series is shared.
how to work out the current in a circuit, given voltage and resistance of the resistors
I = V/ TOTAL RESISTANCE of resistors
Potential dividers equation x2
Vin/R total = vout /R2
Vin / r1+r2 = v out /r2
equation for potential difference involving emf and vout
or vin and vout
emf - vout = Potential difference
What is the equation for internal resistance and meaning of symbols
E - v - ir = 0
E is epsilon = emf
V = the potential difference across terminal
I is the current in series circuit
r is the internal resistance
What is the load resistance
resistance in the wire/circuit used to get current when you have PD across terminal
