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

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 air is (A) 4.5 × 10-2 N (B) 4.5 × 10-3 N (C) 5.4 × 10-2 N (D) 5.4 × 10-3 N

Tardigrade Admin · Accepted Answer

Here, q1 = 1 × 10-7 C, q2 = 2 x× 10-7 C, r = 20 cm = 20 × 10-2 m As F=(q1 q2/4πε0r2)=(9×109×1×10-7×2×10-7/(20×10-2)2) =4.5×10-3 N

Q. The force between two small charged spheres having charges of $1 \times 1 0^{- 7} C$ and $2 \times 1 0^{- 7} C$ placed $20 c m$ apart in air is

$4.5 \times 1 0^{- 2} N$

$4.5 \times 1 0^{- 3} N$

$5.4 \times 1 0^{- 2} N$

$5.4 \times 1 0^{- 3} N$

Here, $q_{1} = 1 \times 1 0^{- 7} C$ , $q_{2} = 2 x \times 1 0^{- 7} C$ ,
$r = 20 c m = 20 \times 1 0^{- 2} m$
As $F = \frac{q _{1} q _{2}}{4 π ε _{0} r ^{2}} = \frac{9 \times 1 0 ^{9} \times 1 \times 1 0 ^{- 7} \times 2 \times 1 0 ^{- 7}}{( 20 \times 1 0 ^{- 2} ) ^{2}}$
$= 4.5 \times 1 0^{- 3} N$

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

4.5×10−2N

4.5×10−3N

5.4×10−2N

5.4×10−3N

Here, q1​=1×10−7C, q2​=2x×10−7C, r=20cm=20×10−2m As F=4πε0​r2q1​q2​​=(20×10−2)29×109×1×10−7×2×10−7​ =4.5×10−3N

Q. The force between two small charged spheres having charges of $1 \times 1 0^{- 7} C$ and $2 \times 1 0^{- 7} C$ placed $20 c m$ apart in air is

$4.5 \times 1 0^{- 2} N$

$4.5 \times 1 0^{- 3} N$

$5.4 \times 1 0^{- 2} N$

$5.4 \times 1 0^{- 3} N$