If two conducting spheres are separately charged and then brought in contact—

When two conducting spheres are separately charged and then brought into contact, the total charge on the two spheres is conserved. According to the principle of conservation of charge, charge can neither be created nor destroyed, only transferred between bodies. When contact occurs, charges flow from the sphere at a higher potential to the one at a lower potential until their potentials equalize [2]. While the total charge remains constant, the total electrostatic energy is generally not conserved. During the redistribution of charges, some energy is dissipated as heat due to the resistance of the conductors or as electromagnetic radiation during the sparking/flow process [3]. The final potential depends on the capacities (radii) of the spheres and is not necessarily the arithmetic mean of the original potentials unless the spheres are identical. Thus, only the conservation of charge holds true in all cases.

Sources

1. [2] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > 11.7 HEA 11.7 HEA11.7 HEATING EFFECT OF ELECTRIC CURRENT > p. 188
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > Figure 11.3 > p. 176