The electric intensity due to a dipole of length 10 cm and

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The electric intensity due to a dipole of length 10 cm and having a charge of 500 µC, at a point on the axis at a distance 20 cm from one of the charges in air, is

1. 6.25 × 10⁷ N/C
2. 9.28 × 10⁷ N/C
3. 13.1 × 10¹¹ N/C
4. 20.5 × 10⁷ N/C

Correct Option: A

Given : Length of the dipole (2l) =10cm = 0.1m or l = 0.05 m
Charge on the dipole (q) = 500 µC = 500 ×10^–6 C and distance of the point on the axis from the mid-point of the dipole (r) = 20 + 5 = 25 cm = 0.25 m.
We know that the electric field intensity due to dipole on the given point

(E) =	1	×	2(q.2l)r
	4πε₀		(r² - l²)²

= 9 × 10⁹ ×	2(500 × 10^–6 × 0.1) × 0.25
	[(0.25)² - (0.05)²]²

=	225 × 10³	= 6.25 × 10⁷ N / C
	3.6 × 10³