Physics · Electric charges: conservation of charge, Coulomb's law forces between two point charges, forces between multiple charges, superposition principle and continuous charge distribution

Three small spheres, each carrying a charge are placed on the circumference of a

Three small spheres, each carrying a charge \( q \) are placed on the circumference of a circle of radius \( R \) forming an equilateral triangle. If we place another charge \( Q \) at the center of the circle, then the force on \( Q \) will be

  • A. zero
  • B. \( \frac{1}{4 \pi \epsilon_{0}} \times \frac{q Q}{R^{2}} \)
  • C. \( \frac{1}{4 \pi \epsilon_{0}} \times \frac{2 q Q}{R^{2}} \)
  • D. \( \frac{1}{4 \pi \epsilon_{0}} \times \frac{3 q Q}{R^{2}} \)

Step-by-step solution

The three charges at the vertices of an equilateral triangle exert forces on the central charge that are equal in magnitude and separated by 120°, so the vector sum is zero.
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