Question

Two small conducting spheres of equal radius have charges +10 µC and -20 µC respectively and placed at a distance R from each other experience force F₁· If they are brought in contact and separated to the same distance, they experience force F₂. The ratio of F₁ to F₂ is ____________.

पर्याय

• 1 : 8

• - 8 : 1

• 1 : 2

• - 2 : 1

Answer 1

Two small conducting spheres of equal radius have charges +10 µC and -20 µC respectively and placed at a distance R from each other experience force F₁· If they are brought in contact and separated to the same distance, they experience force F₂. The ratio of F₁ to F₂ is - 8 : 1.

Explanation:

`"F" prop "q"_1 "q"_2`

When two identical conductors having charges q₁ and q₂ are kept in contact and separated later then each has charge of `(("q"_1 + "q"_2)/2).`

If charges are q₁ and - q₂, then, each has charge `(("q"_1 - "q"_2)/2).`

`therefore  (10-20)/2 = 5 mu"C"`

`therefore  "F"_1/"F"_2 = ("q"_1 "q"_2)/("q'"_1 "q'"_2)`

`= (10 xx -20)/(-5 xx -5)`

`= -8/1`