Question

What is the force between two small charged spheres having charges of 2 × 10–7 C & 3 × 10–7 C placed 30 cm apart in air?

Answer 1

Given:

Q1 = 2 × 10-7 C

Q2 = 3 × 10-7 C

r = 30 × 10-2 m

We know,  

F = (Q1 Q2)/(4 π εo r2 )

Substituting the given values, we get

F = 6 × 10-3 N.

Answer 2

Hello friends.

According to Coulombs law,

F = KQ₁Q₂/r²

where , Q₁ and Q₂ are charges and r is the separation between charges .

Given, Q₁ = 2 × 10⁻⁷C

Q₂ = 3 × 10⁻⁷C

r = 30cm = 0.3 m

K = 9 × 10⁹ Nm²/C²

∴ F = 9 × 10⁹ × 2 × 10⁻⁷ × 3 × 10⁻⁷/(0.3)²

= 9 × 10⁹ × 6 × 10⁻¹⁴/0.09

= 6 × 10⁻³N

Hence, force = 6 × 10⁻³ N

hope it's helpful for you..

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