If the charge on four glass rods are 2q, -q, -5q and 3q respectively, then the total charge stored in the system is:

CONCEPT:

Electric Charge

• It is defined as the intrinsic property of certain fundamental particles like electrons, proton, etc, due to which they produce electric and magnetic effects.
• Types of electric charge
  1. ​Positive charge: A body having a deficiency of electrons.
  2. ​Negative charge: A body having an excess of electrons.
• Properties of electric charge
  • Like charges repel and unlike charges attract each other.
  • A charge is a scalar quantity.
  • Additivity of charge: If a system contains a number of point charges, then the total charge of the system is obtained simply by adding all the charges algebraically.
  • A charge is always quantized.
  • A charge will always remain conserved.
  • A charge is always associated with mass.
  • The unit of charge is the coulomb.

⇒ 1 coulomb = charge on 625 × 1016 electrons

CALCULATION:

Given q₁ = 2q, q2 = -q, q3 = -5q and q4 = 3q

Additivity of charge:

• If a system contains a number of point charges, then the total charge of the system is obtained simply by adding all the charges algebraically.
• The total charge of the system that contains n number of charges is given as,

⇒ q = q₁ + q2 + q3 + ... + q_n

So the total charge stored in the system is,

⇒ q = q1 + q2 + q3 + q₄

⇒ q = 2q - q - 5q + 3q

⇒ q = -q

• Hence, option 1 is correct.