Two insulated charged metallic spheres P and Q have their centres separated by a distance of 60 cm. The radii of P and Q are negligible compared to the distance of separation. The mutual force of electrostatic repulsion if the charge on each is 3.2 × 10-7 C is

Question

Two insulated charged metallic spheres P and Q have their centres separated by a distance of 60 cm. The radii of P and Q are negligible compared to the distance of separation. The mutual force of electrostatic repulsion if the charge on each is 3.2 × 10-7 C is (A) 5.2 × 10-4 N (B) 2.5 × 10-3 N (C) 1.5 × 10-3 N (D) 3.5 × 10-4 N

Tardigrade Admin · Accepted Answer

Here, q1 = q2 = 3.2 × 10-7 C, r = 60 cm = 0.6 m Electrostatic force, F=(1/4πε0r2) (q1 q2/r2)=(9×109(3.2×10-7)2/(0.6)2) =25.6×10-3 N

Q. Two insulated charged metallic spheres $P$ and $Q$ have their centres separated by a distance of $60 c m$ . The radii of $P$ and $Q$ are negligible compared to the distance of separation. The mutual force of electrostatic repulsion if the charge on each is $3.2 \times 1 0^{- 7} C$ is

$5.2 \times 1 0^{- 4} N$

$2.5 \times 1 0^{- 3} N$

$1.5 \times 1 0^{- 3} N$

$3.5 \times 1 0^{- 4} N$

Here, $q_{1} = q_{2} = 3.2 \times 1 0^{- 7} C$ , $r = 60 c m = 0.6 m$
Electrostatic force,
$F = \frac{1}{4 π ε _{0} r ^{2}} \frac{q _{1} q _{2}}{r ^{2}} = \frac{9 \times 1 0 ^{9} ( 3.2 \times 1 0 ^{- 7} ) ^{2}}{( 0.6 ) ^{2}}$
$= 25.6 \times 1 0^{- 3} N$

Q. Two insulated charged metallic spheres P and Q have their centres separated by a distance of 60cm. The radii of P and Q are negligible compared to the distance of separation. The mutual force of electrostatic repulsion if the charge on each is 3.2×10−7C is

5.2×10−4N

2.5×10−3N

1.5×10−3N

3.5×10−4N