Two point charges A and B of magnitude +8 × 10-6 C and -8 × 10-6 C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is 6.4 × 104 NC -1. The distance 'd' between the point charges A and B is:

Question

Two point charges A and B of magnitude +8 × 10-6 C and -8 × 10-6 C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is 6.4 × 104 NC -1. The distance 'd' between the point charges A and B is: (A) 2.0 m (B) 3.0 m (C) 1.0 m (D) 4.0 m

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/adb965987debff6f3c06452a8b0bfa2f-.png" /> E 0=2 × ( Kq /( d / 2)2) ⇒ E 0=8 ( Kq / d 2) ⇒ d 2=(8 × 9 × 109 × 8 × 10-6/6.4 × 104) d =3 m

Q. Two point charges A and B of magnitude +8×10−6C and −8×10−6C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is 6.4×104NC−1. The distance 'd' between the point charges A and B is:

2.0 m

3.0 m

1.0 m

4.0 m

E0​=2×(d/2)2Kq​ ⇒E0​=8d2Kq​ ⇒d2=6.4×1048×9×109×8×10−6​ d=3m

$E_{0} = 2 \times \frac{K q}{( d /2 ) ^{2}}$
$\Rightarrow E_{0} = 8 \frac{K q}{d ^{2}}$
$\Rightarrow d^{2} = \frac{8 \times 9 \times 1 0 ^{9} \times 8 \times 1 0 ^{- 6}}{6.4 \times 1 0 ^{4}}$
$d = 3 m$