Question

Kirchhoff's I and II laws are based on conservation of:

• A. energy and charge
• B. charge and energy
• C. mass and charge
• D. none of the above

Answer 1

Answer: (B)

From Kirchhoff's first law, in an electric circuit, the algebraic sum of the currents meeting at any junction in the circuit is zero, that is
$i_1+i_2+i_3+i_4=0$

$\Rightarrow \sum i=0$
Thus, Kirchhoff's first law expresses the conservation of charge.
Kirchhoff's second law states that in any closed mesh of a circuit, the algebraic sum of the products of current and the resistance in each . part is equal to the algebraic sum of the emfs in that mesh
i.e., $\Sigma iR=\Sigma E$
Hence, second law expresses the conservation of energy.