Question

A line may not be __________

(a) parallel to both the planes

(b) parallel to one plane and perpendicular to the other

(c) parallel to one plane and inclined to the other

(d) perpendicular to both the planes

The question was posed to me by my college professor while I was bunking the class.

I need to ask this question from Projection of Straight Lines topic in portion Orthographic Projection, Projections of Lines, Planes and Solids of Civil Engineering Drawing

Answer 1

The correct answer is (d) perpendicular to both the planes

The explanation: The question is asking about a single line and if a line is perpendicular to both the planes it will never be resembled as a line i.e. it can’t be a single line. If it becomes perpendicular to the planes it will become perpendicular to itself thus forming two lines, as the single to will itself make 90 angle it can’t be further called as a single line.