Engineering Drawing MCQ Quiz - Objective Question with Answer for Engineering Drawing - Download Free PDF

Explanation:

Dimensions in "mm" for different sizes of drawing sheets are as follows:

Explanation:

Projection Systems:

1. First angle projection system  2. Third angle projection system

• Both third angle and first-angle projection display the standard three orthographic views of a part or assembly.

• The key difference between third angle and first angle is the layout of the part on the sheet.

​1. First angle projection system:​

• In first angle projection, top view is located below the front view.

​2.  Third angle projection system:

• In Third angle projection top view is located above the front view.

Additional Information

Orthographic Projection:

Orthographic Projections is a technical drawing in which different views of an object are projected on different reference planes observing perpendicular to respective reference plane.

• Horizontal Plane (HP)
• Vertical Plane (VP)

• Side or Profile Plane (PP)

• Front View (FV) – Projected on VP
• Top View (TV) – Projected on HP
• Side View (SV) – Projected on PP
   

Explanation:

As per IS 9609 (Part 0): 2001, Clause 3.3

Lettering:

• Procedure of writing graphic characters taken from a graphic character set on a (technical) drawing carrier (in addition to the graphical representation).
• The whole of the non-graphical information on a (technical) drawing carrier (text, instructions, dimensions, etc.).
• The whole of the graphic characters of a graphic character set which can be used for transferring non-graphical information onto a (technical) drawing carrier.

Dimensioning of lettering type 'A':

In lettering A type the height of the capital letter is divided into 14 parts.

Important Points

• In lettering B type the height of the capital letter is divided into 10 parts.
• According to the Bureau of Indian Standards the range of nominal size of letters has been specified as follows: 1.8 m, 2.5 mm, 3.5 mm, 5 mm, 7 mm, 10 mm, 14 mm and 20 mm.
• Space between the lines is 3/10 h (height of capital letters).
• Space between the words may be equal to the width of the alphabet M or 3/5 h (height of capital letters).
• Drawing title is written in 7 mm size.
• Drawing numbers, title block, and letters denoting the cutting planes and sections are written in 10 mm size.

Explanation:

A Plan Drawing is a horizontal view of a building or structure, cut at a height of about 1.2 meters (4 feet) above the floor level.

It shows the layout of:

• Walls, Doors, and Windows: Placement and measurements.

• Furniture Layout: Beds, tables, chairs, and other furnishings.

• Electrical Points: Locations for outlets, switches, and lighting fixtures.

• Plumbing Lines: Water supply and drainage systems.

• HVAC Ducts: Air conditioning vents and heating systems.

Types of Plans:

• Floor Plans: General layout of each floor.

• Furniture Plans: Specific layout of furniture arrangements.

• Reflected Ceiling Plans (RCP): Positioning of lights and HVAC on ceilings.

Purpose:

• To visualize how spaces are organized internally.

• To guide builders and electricians during installation.

Explanation:

A Horizon Line is an important element in perspective drawings, representing the observer's eye level.

It is the point where:

• The ground plane and the sky appear to meet in the distance.

• All horizontal parallel lines converge towards vanishing points.

Types of Perspective Drawings:

• One-Point Perspective: A single vanishing point; often used for interiors.

• Two-Point Perspective: Two vanishing points; commonly used for building exteriors.

• Three-Point Perspective: Adds a third vanishing point for height representation.

Purpose of the Horizon Line:

• It acts as a reference for the height of objects in the drawing.

• It guides the placement of buildings, roads, and infrastructure in realistic perspective.

The correct answer is 120-degree.

Key Points

• Draw horizontal and vertical lines to represent an isometric object.
• While horizontal lines are drawn at a 30-degree angle to the horizontal plane, vertical lines remain vertical.
• All three axes must be at a 120-degree angle from one another. Now, if you adhere to rule number 1, this is accomplished automatically.
• An object's three faces are all equally foreshortened in the isometric projection.
• Any mechanical drawing or system is typically explained with an isometric drawing.
• It can be found on instructions for model kits like Lego, Gundam, and others, as well as mechanical infographics. 

Internal Angle and External Angle can be seen in the diagram below.

Explanation:

Scales are used to make drawings of the objects to the proportionate size desired. 

A scale is defined as the ratio of the linear dimensions of element of the object as represented in drawing to the actual dimensions of the same element of the object itself.

In this case, the relation between the dimension on the drawing and the actual dimension of the object is mentioned numerically in the style as 10 mm = 5m, etc.

BIS recommends eight set-scales in plastic/cardboard with designations MI, M2 and so on as shown in table.

Explanation:

Perspective View: These are most realistic drawings. Our eyes see objects in perspective. There are three types of perspective projections: one, two- and three-point perspective projections.

Oblique Projection: These are least realistic. Only one or two faces in oblique projections have true shape and size. There are three types of oblique projections: cabinet, cavalier and general.

Axonometric Projection: These are more realistic than oblique. Horizontal edges of an object in axonometric projections are parallel to each other and inclined to the plane. There are three types of axonometric projections: isometric, dimetric and trimetric.

Isometric (meaning “equal measure”) is a type of parallel (axonometric) projection, where the X and Z axes are inclined to the horizontal plane at the angle of 30⁰. The angle between axonometric axes equals 120⁰.

If a line is parallel to V. P. and inclined to H. P., its top view will be of smaller dimension.

If a line is parallel to H. P. and inclined to V. P., it's front view will be of smaller dimension.

a’b’ = AB cosθ 

Explanation:

• Abbreviations and symbols for engineering drawings are used to express and detail the features of an engineering drawing.
• This contains abbreviations common to the language of individuals who work in the manufacture and inspection of parts and assemblies with engineering drawings.

Explanation:

The leader is never drawn vertical or horizontal or curved. It is drawn at a convenient angle of not less than 30o to the line to which it touches. When pointing to a circle or an arc it is drawn radially.

A leader line is a line referring to a feature (dimension, object, outline etc). It is a continuous thin line.

• If the leader line ends within the outline of an object, it should have a dot at the end.
• It should have an arrowhead if it ends on the outline of an object.
• It should terminate without dot or arrowhead if it ends on a dimension line.​

Representation Factor (R. F)

\({\rm{R}}.{\rm{F}} = {\rm{}}\frac{{{\rm{Length\;of\;object\;on\;drawing}}}}{{{\rm{Actual\;length\;of\;the\;object}}}} = \frac{{\cos 45^\circ }}{{\cos 30^\circ }} = \frac{{1/\sqrt 2 }}{{\sqrt 3 /2}} = \sqrt {\frac{2}{3}} \)

A circle has an eccentricity of zero, so the eccentricity shows you how "un-circular" the curve is. Bigger eccentricities are less curved.

Different values of eccentricity make different curves:

At eccentricity = 0 we get a circle

for 0 < eccentricity < 1 we get an ellipse

for eccentricity = 1 we get a parabola

for eccentricity > 1 we get a hyperbola

for infinite eccentricity, we get a line

Explanation:

Datum plane:

• A theoretical plane or axis is established by real features on an object for the purpose of defining the datum reference frame.
• A datum is a theoretical exact plane, axis or point location that GD&T or dimensional tolerances are referenced to.

Datum reference frame:

• A system of three mutually perpendicular planes is used as the coordinate system for geometric dimensioning.