A system has two charges q₁ = 2.5 × 10⁻⁷C and q₂ = –2.5 × 10⁻⁷ C located at points A: (0, 0, –15 cm) and B: (0,0, +15 cm), respectively. What are the total charge and electric dipole moment of the system?

Imagine both the charges located in a coordinate frame of reference.

At A, amount of charge, q_A = 2.5 x 10^_7C

At B, amount of charge, q_B = —2.5 x 10^-7 C

Total charge of the system, q = q_A + q_B = 2.5 x 10^_7 C – 2.5 x 10^-7C = 0

Distance between two charges at points A and B, d= 15 + 15 = 30 cm = 0.3 m

Then Electric dipole moment of the system is given by,

p = q_Ax d = q_Bx d = 2.5 x 10^_7 x 0.3 = 7.5 x 10~⁸ C m along positive z-axis

Therefore, the electric dipole moment of the system is 7.5 x 10~⁸ C m along positive z-axis.