Physics Chapter 9: Kirchhoff's Laws

PHYSICS DEFINITION:

Kirchhoff’s First Law: The Sum of the currents entering any point in a circuit is equal to the sum of the currents leaving the same point.

Kirchhoff’s Second Law: The Sum of the EMFs around any loop in a circuit is equal to the sum of p.d.s around the loop.

 

PHYSICS KEYWORD LIST:

Conservation of charge: Electric charge can neither be created nor destroyed.

 

PHYSICS CHAPTER WISE SUMMARY:

Kirchhoff’s first law states that the sum of current currents entering any point in a circuit is equal to the sum of the currents leaving that point.

Kirchhoff’s second law states that the sum of EMFs around any loop in a circuit is equal to the sum of pds around the loop.

The combined resistance of resistors in series: R = R1+ R2+ R3...

The combined resistance of resistors in parallel: (1/R) = (1/R1) + (1/R2) + (1/R3)...

Ammeters have a low resistance and are connected in series in a circuit.

Voltmeters have a high resistance and are connected in parallel in a circuit.

 

PHYSICS IMPORTANT NOTES:

∑I in = ∑I out

∑EMF = ∑V

Resistance in series: R = R1+ R2+ R3…

Resistance in parallel: (1/R) = (1/R1) + (1/R2) + (1/R3)...