Question

State Kirchhoff's rules. Explain briefly how these rules are justified.

Answer 1

Kirchhoff’s First Law − Junction Rule In an electrical circuit, the algebraic sum of the currents meeting at a junction is always zero. I1, I2 I3, and I4 are the currents flowing through the respective wires. Convention: The current flowing towards the junction is taken as positive. The current flowing away from the junction is taken as negative. I3 + (− I1) + (− I2) + (− I4) = 0 This law is based on the law of conservation of charge.
 
Kirchhoff’s Second Law − Loop Rule In a closed loop, the algebraic sum of the emfs is equal to the algebraic sum of the products of the resistances and the currents flowing through them. For the closed loop BACB: E1 − E2 = I1R1 + I2R2 − I3R3 For the closed loop CADC: E2 = I3R3 + I4R4 + I5R5
This law is based on the law of conservation of energy.

Answer 2

Hey !!

There are mainly 2 laws

1) Junction Law

2) Loop Law

1st Law :- It is known as junction rule which means that for a given junction or node in a circuit, sum of the currents entering will be equal to sum of currents leaving the junction.

2nd Law :- It is known as loop law which shows that around any closed loop in a circuit, sum of the potential differences across all elements will be zero.

JUSTIFICATION

The junction rule is in accordance with the conservation of charge that serves as basis of current rule while loop rule is based on law of conservation of energy.

GOOD LUCK !!