AIIMS2003PhysicsElectrostatics
Three charges are placed at the vertices of an equilateral triangle of side a as shown in the given figure. The force experienced by the charge placed at the vertex A in a direction normal to B C is
Options
- AQ^2 4 ₀ a^2
- B-Q^2 (4 ₀ a^2 )
- Czero
- DQ^2 2 ₀ a^2 .
Correct answer
C. zero
Step-by-step solution
The force experienced by A due to B is F₁= 1 4 ₀ Q Q a^2 along A B (attractive) The force experienced by A due to C is F₂= 1 4 ₀ Q^2 a^2 along C A produced (repulsive) Now the force F ₁ is having a component F₁ 30^ along and the force F ₂ is having a component F₂ 30^ along A E , A E and A F are both normal to B C but they are mutually opposite to each other. And as | F ₁ |= | F ₂ | , so the forces along A E and A F will both cancel each other. And so the force experienced by the charge at A in the direction normal