How many of the following statements about electric field lines are correct?
(i) In a region of constant electric field, the field lines are parallel straight lines with equal spacing.
(ii) The number of field lines that can be drawn around a given charge has one fixed value.
(iii) An arrow is put on a field line, because a tangent alone can point in two opposite directions.
(iv) The field lines around two equal positive charges show the attraction between the two charges.
(v) No field line crosses a small flat area that is held parallel to the field lines.
(vi) For a point charge, a given solid angle (a narrow cone with its tip at the charge) holds more field lines far from the charge than near it.
(vii) Faraday, who first used the picture of field lines, called them lines of force.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Four
A field line is drawn so that the tangent at each point gives the direction of the field there. The closeness of the lines shows how strong the field is. The total number of lines drawn is only a matter of choice.
The statements that are correct:
(i) Constant field: parallel, equally spaced straight lines — correct
(iii) The arrow picks one of the two directions along the tangent — correct
(v) No line crosses an area held parallel to the lines — correct
(vii) Faraday called them lines of force — correct
The statements that are not:
(ii) One fixed number of lines — any number of lines can be drawn; only their relative closeness matters
(iv) Attraction between two equal positive charges — their field lines show repulsion
(vi) More lines far away in the same solid angle — the number of lines in a given solid angle is the same at every distance
Number of correct statements = 4
NCERT (2026-27):
Summary – “In regions of constant electric field, the field lines are uniformly spaced parallel straight lines.”
Electric Field Lines – “Another person may draw more lines. But the number of lines is not important. In fact, an infinite number of lines can be drawn in any region.”
“… An arrow on the curve is obviously necessary to specify the direction of electric field from the two possible directions indicated by a tangent to the curve. …”
“… The field lines around a system of two positive charges (q, q) give a vivid pictorial description of their mutual repulsion, …”
“… We know that in a given solid angle the number of radial field lines is the same. …”
“The picture of field lines was invented by Faraday … Faraday called them lines of force. …”
Electric Flux – “… When θ = 90°, field lines will be parallel to ΔS and will not cross it at all …”