Electrical circuits Flashcards
1
Q
What is Kirchhoff’s first law - the la of current?
A
The sum of current into a junction = the sum of current out of a junction
or
at a circuit junction, the sum of the charge flowing into the junction equals the sum of the charge flowing out of the junction.
2
Q
What is Kirchhoff’s second law - the law of voltage
A
In a closed circuit loop, the sum of the PD = the sum of the EMF
The PD of 4 resistors in two sets of parallel resistors , both sets have a PD = to the emf
3
Q
What is the resistance of an ideal ammetre?
A
0
4
Q
What is the resistance of an ideal voltmeter?
A
infinite
5
Q
what is the current in parallel?
A
I_total = V_total/R1 + V_total/R2 + V_total/R3 …
6
Q
What is the resistance in parallel?
A
1/R_Total = 1/R1 +1/R2 + 1/R3 …
