Question

The ________ planes are so selected as to cut the surface of one of the solids in straight lines and that of the other in straight lines or circles.

(a) line

(b) cutting

(c) horizontal

(d) xy

The question was asked by my college director while I was bunking the class.

This question is from Intersection of Surfaces topic in division Development of Surfaces, Isometric Projections, Perspective Projections & Transformation of Projections of Civil Engineering Drawing

Answer 1

Correct answer is (a) line

Explanation: Line method: A number of lines are drawn on the lateral surface of one of the solids and in the region of the line of intersection. Points of intersection of these lines with the surface of the other solid are then located.  These points will lie on the required line of intersection. They are more easily located from the view in which the lateral surface of the second solid appears edgewise (i.e. as a line). The curve drawn through these points will be the line of intersection.

Cutting-plane method: The two solids are assumed to be cut by a series of cutting planes. The cutting planes may be vertical (i.e. perpendicular to the H.P.), edgewise (i.e. perpendicular to the V.P.) or oblique.  The cutting planes are so selected as to cut the surface of one of the solids in straight lines and that of the other in straight lines or circles.