⚛️ Physics · Electric Charges and Fields · NEET & JEE

A point charge of 8 µC lies inside a closed surface. The net electric flux through the surface is (take ε0 = 8.85 × 10-12 C2 N-1 m-2):

Answer: 9.0 10 5 N m 2 /C.

A 4.5 × 105 N m2/C
B 8.0 × 105 N m2/C
C 1.8 × 106 N m2/C
D 9.0 × 105 N m2/C

Correct answer: D. 9.0 × 105 N m2/C

Explanation: By Gauss law the flux depends only on the enclosed charge: Φ = q/ε0 = 8 × 10-6/8.85 × 10-12 ≈ 9.0 × 105 N m2/C, independent of the surface shape or size.

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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A point charge of 8 &micro;C lies inside a closed surface. The net electric flux through the surface is (take &epsilon;<sub>0</sub> = 8.85 &times; 10<sup>-12</sup> C<sup>2</sup> N<sup>-1</sup> m<sup>-2</sup>):

Concept context

More Electric Charges and Fields questions

A point charge of 8 µC lies inside a closed surface. The net electric flux through the surface is (take ε<sub>0</sub> = 8.85 × 10<sup>-12</sup> C<sup>2</sup> N<sup>-1</sup> m<sup>-2</sup>):