Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Field and Potential
Three charges are placed at the vertices of an equilateral triangle as illustrated in the figure. Determine the dipole moment of the combination.
Options
- A2 qd , along the bisector of the angle at 2q , away from the triangle
- B3 qd , along the bisector of the angle at 2q , towards the triangle
- C3 qd , along the bisector of the angle at 2q , away from the triangle
- Dqd , along the bisector of the angle at 2q , towards the triangle
Correct answer
C. 3 qd , along the bisector of the angle at 2q , away from the triangle
Step-by-step solution
The system of charges can be considered as two electric dipoles by splitting the 2q charge into two +q charges. Let the vertices be A (top, -q ), B (bottom-left, 2q ), and C (bottom-right, -q ). The first dipole is formed by -q at A and +q at B . Its dipole moment p ₁ has magnitude qd and is directed from A to B . The second dipole is formed by -q at C and +q at B . Its dipole moment p ₂ has magnitude qd and is directed from C to B . The angle between the vectors p ₁ and p ₂ is 60^ , which is the interior angle of