Civil war Day 21-LSGD-ED Projections

Any object below Horizontal Plane (H.P.) and behind Vertical Plane (V.P.), the object is in ...... quadrant

• 1st quadrant
• 2nd quadrant
• 3rd quadrant
• 4th quadrant

Answer explanation

Objects below H.P. and behind V.P. lie in the 3rd quadrant, where both coordinates are negative with respect to the reference planes.

This type of projection is when projectors are parallel to each other, but are at an angle other than 90 degrees to the plane of projection

• Orthographic projection
• Oblique projection
• Angular projection
• Isometric projection

Answer explanation

In oblique projection, projectors are parallel but inclined at an oblique angle (other than 90°) to the projection plane, unlike orthographic projection where projectors are perpendicular.

A circle is placed 35° with vertical; the view from the top will be

• Line
• Circle
• Ellipse
• Sphere

Answer explanation

When a circle is inclined to the plane of projection (here 35° to V.P.), its projection appears as an ellipse in the top view due to foreshortening of one axis.

The angle made by the profile plane with the reference planes is

• 30°
• 60°
• 45°
• 90°

Answer explanation

The profile plane is always perpendicular (90°) to both the horizontal plane (H.P.) and the vertical plane (V.P.), used for projecting side views.

The two planes employed for the purpose of orthographic projections are called

• Reference plane
• Principal plane
• Both A and B
• None of these

Answer explanation

The Horizontal Plane (H.P.) and Vertical Plane (V.P.) are known as reference or principal planes used for orthographic projection.

The ratio of isometric length to true length is

• 0.625
• 0.725
• 0.815
• 0.825

Answer explanation

The isometric length is equal to 0.815 (≈0.816) times the true length, due to foreshortening along all three isometric axes equally at 30° from the horizontal.

If a plane is inclined to both H.P. and V.P., then its plan is

• True size and shape
• A line
• Distorted
• Any of these

Answer explanation

When a plane is inclined to both the Horizontal Plane (H.P.) and Vertical Plane (V.P.), its projections are foreshortened and distorted, not showing the true shape.

If a square plane is rectangular in its elevation, then

• The plane is parallel to H.P.
• The plane is inclined to V.P.
• The plane is normal to V.P.
• The plane is parallel to V.P.

Answer explanation

When a square plane appears as a rectangle in elevation, it indicates the plane is inclined to the Vertical Plane (V.P.) but parallel to the Horizontal Plane (H.P.).

One-point perspective is also known as

• Parallel perspective
• Two-view perspective
• Angular perspective
• Perpendicular perspective

Answer explanation

In one-point (parallel) perspective, all lines parallel to the viewer’s line of sight converge at a single vanishing point, hence it is called parallel perspective.

A line is perpendicular to the horizontal plane. Its horizontal trace coincides with its _____

• Front view
• Top view
• Side view
• Isometric view

Answer explanation

the horizontal trace (H.T.) of a line perpendicular to the horizontal plane coincides with its top view (plan)