Question

There are two small uncharged spheres placed at a distance of 1m from each other.N number of electrons are transferred from one sphere to another. The force between the spheres is now measured to be equal to 2 newton then the value of N is

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Answer 1

Answer:

Charge on the first sphere, q 1

=2×10 −7C

Charge on the second sphere, q 2

=3×10 −7C

Distance between the spheres, r=30cm=0.3m

F= 4πε 0 r 2q 1q 2

Where, ε 0

= Permittivity of free space

4πε 01

=9×10 9 Nm 2 C −2

F= (0.3) 2 9×10 9 ×2×10 −7 ×3×10 −7 =6×10 −3 N

Hence, force between the two small charged spheres is 6×10 −3

N. The charges are of same nature. Hence, force between them will be repulsive.