Question

The force between two small charged spheres having charges of 1 × 10⁻⁷ C and 2 × 10⁻⁷ C placed 20 cm apart in the air is:

Options

• 4.5 × 10⁻² N

• 4.5 × 10⁻³ N

• 5.4 × 10⁻² N

• 5.4 × 10⁻³ N

Answer 1

4.5 × 10⁻³ N

Explanation:

Here, q₁ = 1 × 10⁻⁷ C, q₂ = 2 × 10⁻⁷ C,

r = 20 cm = 20 × 10⁻² m

F = `("q"_1"q"_2)/(4πε_0"r"^2)`

= `(9 xx 10^9 xx 1 xx 10^-7 xx 2 xx 10^-7)/((20 xx 10^-2)^2)`

= 4.5 × 10⁻³ N