Saved Bookmarks
| 1. |
The electrostatic force on a small sphere of charge 0.4 muCdue to another small sphere of charge -0.8 uC in air is 0.2 N. (a) What is the distance between the two spheres ? (b) What is the force on the second sphere due to the first ? |
|
Answer» Solution :(a) Coulombian force between two point as charges is, `F = k(q_(1)q_(2))/r^(2)` `therefore -0.2= 9 xx 10^(9)xx (0.4 xx 10^(-6))(-0.8 xx 10^(-6))/r^(2)` (Here, F is attractive and so its value is taken as negative) `therefore r^(2) = (9 xx 10^(9))(4 xx 10^(-7))(8 xx 10^(-7))/(2 xx 10^(-1))` `therefore r^(2) = 144 xx 10^(-4) m^(2)` `therefore r= 12 xx 10^(-2) m = 0.12 m` (b) Here Coulombian force on second sphere due to first sphere is also 0.2 N and attractive in nature because ELECTRIC force is two body force which is always exerted mutually with equal magnitude and opposite directions. |
|