Question

What is the resultant charge in a body whenever the number of protons equals the number of electrons in it?
1. positive charge
2. sometimes positive and sometimes negative
3. zero charge
4. negative charge

Answer 1

Correct Answer - Option 3 : zero charge

Concept:

Basic Properties of charge:

• Charges are additive in nature
• The charge is conserved Quantity
• Quantization of Electric Charge

 

Additivity of Electric Charge

• Consider a system of charges consists of ‘n’ point charges with magnitude q₁, q₂,……q_n. In such a system, the total charge of the system can be obtained by algebraically adding the three charges.
• These charges have the only magnitude but no direction, it is scalar quantities, and are treated like real numbers during operation.
• We note that the charge can either be positive or negative and the operation takes the sign of the charge into consideration.
• For a system containing ‘n’ number of a point charge, the total charge (Q) of the system can be written as,

          Q = q₁ ± q₂ ± ………± q_n

 

Conservation of Electric Charge

• According to the principle of conservation of charges, the charges are neither created nor destroyed, they are only transferred from one body to the other.

 

Quantization of Electric Charge

• According to the principle of quantization of electric charge, all the free charges are integral multiples of a basic predefined unit which we denote by e.
• Thus, the charge possessed by a system can be given as Q = ne
  Where n is an integer value
  And e is the charge on electron or proton given by, ± 1.6 × 10^-19C

 

Calculation:

Given, Number of Proton = Number of Electron

Positive charge = Negative charge

∴ Total charge = 0