Properties of Charges: Practice Problem & Solution

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Properties of Charges. Understanding the underlying formula is key to arriving at the correct answer below:

The mass of the negatively charged sphere increases because:

• When a sphere becomes negatively charged, it gains extra electrons. Since electrons have mass (
  $9.1 \times 10^{-31} \, \text{kg}$ 

  ), the addition of electrons increases the mass of the negatively charged sphere.

• Conversely, the positively charged sphere loses electrons, resulting in a slight decrease in its mass.

Thus, the mass of the negatively charged sphere increases due to the addition of electrons.