If point charges Q1=2 × 10-7 C and Q2=3 × 10-7 C are at 30 cm separation, then find electrostatic force between them

Question

If point charges Q1=2 × 10-7 C and Q2=3 × 10-7 C are at 30 cm separation, then find electrostatic force between them (A) 6× 10-3 N (B) 2× 10-3 N (C) 3× 10-3 N (D) 8× 10-3 N

Tardigrade Admin · Accepted Answer

∵ Electrostatic force, F=k (Q1 Q2/r2) =9 × 109 × (2 × 10-7 × 3 × 10-7/(30 × 10-2)2) =6 × 10-3 N

Q. If point charges $Q_{1} = 2 \times 1 0^{- 7} C$ and $Q_{2} = 3 \times 1 0^{- 7} C$ are at $30 c m$ separation, then find electrostatic force between them

$6 \times 1 0^{- 3} N$

$2 \times 1 0^{- 3} N$

$3 \times 1 0^{- 3} N$

$8 \times 1 0^{- 3} N$

$∵$ Electrostatic force, $F = k \frac{Q _{1} Q _{2}}{r ^{2}}$
$= 9 \times 1 0^{9} \times \frac{2 \times 1 0 ^{- 7} \times 3 \times 1 0 ^{- 7}}{( 30 \times 1 0 ^{- 2} ) ^{2}}$
$= 6 \times 1 0^{- 3} N$

Q. If point charges Q1​=2×10−7C and Q2​=3×10−7C are at 30cm separation, then find electrostatic force between them

6×10−3N

2×10−3N

3×10−3N

8×10−3N