An infinitely long straight wire has a uniform linear charge density of 4 10 -9 C/m. The electric field at a distance of 0.2 m from the wire is approximately:

⚛️ Physics · Electric Charges and Fields · NEET & JEE

An infinitely long straight wire has a uniform linear charge density of 4 × 10-9 C/m. The electric field at a distance of 0.2 m from the wire is approximately:

Answer: 360 N/C.

A 180 N/C
B 90 N/C
C 720 N/C
D 360 N/C

Correct answer: D. 360 N/C

Explanation: For an infinite line charge, E = λ/(2πε0r) = 2kλ/r = 2 × 9 × 109 × 4 × 10-9/0.2 ≈ 360 N/C.

Field lines always point from positive to negative charge, are denser where the field is stronger, and never cross; an isolated positive charge has lines radiating symmetrically outward, while a dipole's lines curve from the positive to the negative charge.

Concept context

Coulomb's law, electric field, potential, capacitors, Gauss's law.

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An infinitely long straight wire has a uniform linear charge density of 4 &times; 10<sup>-9</sup> C/m. The electric field at a distance of 0.2 m from the wire is approximately:

Concept context

More Electric Charges and Fields questions

An infinitely long straight wire has a uniform linear charge density of 4 × 10<sup>-9</sup> C/m. The electric field at a distance of 0.2 m from the wire is approximately: