KCET2010PhysicsElectrostatics
Two small spheres of masses M ₁ and M ₂ are suspended by weightless insulating threads of lengths L ₁ and L ₂ . The spheres carry charges Q₁ and Q₂ respectively. The spheres are suspended such that they are in level with one another and the threads are inclined to the vertical at angles of ₁ and ₂ as shown. Which one of the following conditions is essential, if ₁= ₂ ?
Options
- AM ₁ M ₂ , but Q ₁= Q ₂
- BM ₁= M ₂
- CQ₁=Q₂
- DL ₁= L ₂
Correct answer
B. M ₁= M ₂
Step-by-step solution
For sphere 1, in equilibrium array ll and & T ₁ ₁= M ₁ ~g ~T ₁ ₁= F ₁ array ₁= F ₁ M ₁ g Similarly for sphere 2, ₂= F₂ M₂ g F is same on both the charges, will be same only if their masses M are equal.