Unit 2: Orthographic Projection Overview
Engineering Graphics Unit 2 focuses on orthographic projection and projection methods. Orthographic projection is used to represent a 3D object into 2D views using perpendicular projectors.
This unit is very important for RGPV exams because projection of straight lines, projection of planes, true length and true inclination questions are repeatedly asked.
Unit 2 Syllabus
- Principles of Orthographic Projection
- Conventions in Orthographic Projection
- Projection of Points
- Projection of Lines inclined to HP and VP
- Projection of Planes inclined to HP and VP
- Auxiliary Planes
- First Angle Projection
- Third Angle Projection
- True Length and True Inclinations
- Auxiliary Vertical Plane
- Auxiliary Inclined Plane
Most Important Topics for Exam
Projection of Lines
Most repeated drawing question, especially lines inclined to HP and VP.
Projection of Planes
Very important for pentagon, hexagon, rhombus and rectangular lamina problems.
Orthographic Projection
Common theory question with first angle and third angle projection.
Auxiliary Planes
Important for finding true length, true shape and inclinations.
Projection of Points
Basic but important topic involving different quadrants.
True Length
Frequently asked with line projection numericals.
Short Notes for Quick Revision
1. Orthographic Projection
Orthographic projection is a method of representing a three-dimensional object in two-dimensional views using perpendicular projectors.
2. Main Views
The main views in orthographic projection are front view, top view and side view.
3. Horizontal Plane
Horizontal Plane, also called HP, is the plane on which top view is projected.
4. Vertical Plane
Vertical Plane, also called VP, is the plane on which front view is projected.
5. XY Line
XY line is the reference line between HP and VP. It is drawn first before solving projection problems.
6. First Angle Projection
In first angle projection, object is placed in the first quadrant. Views are placed opposite to the direction of observation.
7. Third Angle Projection
In third angle projection, object is placed in the third quadrant. Views are placed on the same side as the direction of observation.
8. Projection of Points
Projection of points depends on the position of the point with respect to HP and VP. A point may lie in first, second, third or fourth quadrant.
9. Projection of Lines
Projection of lines is used to represent straight lines inclined to HP, VP or both planes. Important terms are true length, apparent length and inclinations.
10. Projection of Planes
Projection of planes includes projection of plane figures such as triangle, square, pentagon and hexagon when inclined to HP or VP.
11. Auxiliary Planes
Auxiliary planes are additional planes used to obtain true shape, true size and true length of inclined objects.
12. Auxiliary Vertical Plane
Auxiliary Vertical Plane is perpendicular to HP and inclined to VP. It is used for auxiliary views.
13. Auxiliary Inclined Plane
Auxiliary Inclined Plane is inclined to HP and perpendicular to VP. It is used to find true shapes of inclined surfaces.
Important Terms Table
| Term | Meaning |
|---|---|
| HP | Horizontal Plane where top view is projected |
| VP | Vertical Plane where front view is projected |
| XY Line | Reference line between HP and VP |
| True Length | Actual length of a line |
| Apparent Length | Projected length of a line |
| θ | Inclination of line with HP |
| φ | Inclination of line with VP |
| AVP | Auxiliary Vertical Plane |
| AIP | Auxiliary Inclined Plane |
Quadrants in Projection of Points
| Quadrant | Position of Point |
|---|---|
| First Quadrant | Above HP and in front of VP |
| Second Quadrant | Above HP and behind VP |
| Third Quadrant | Below HP and behind VP |
| Fourth Quadrant | Below HP and in front of VP |
Important Questions
- Define Orthographic Projection and explain its principles.
- Differentiate between First Angle Projection and Third Angle Projection.
- Explain conventions used in Engineering Drawing.
- Explain Auxiliary Planes and their applications.
- Explain methods for finding true length and true inclinations of lines.
- Explain projections of points in different quadrants.
- Write short note on Auxiliary Vertical Plane.
- Write short note on Auxiliary Inclined Plane.
- Draw projections of a line inclined to HP and parallel to VP.
- Draw projections of a line inclined to both HP and VP.
- Determine true length and true inclinations of a line.
- Draw projections of a pentagonal lamina inclined to HP.
- Draw projections of a hexagonal lamina inclined to VP.
- Draw projections of a rhombus inclined to both planes.
PYQ Analysis Table
According to the uploaded Unit 2 PYQ analysis, projection of straight lines, projection of planes, true length and orthographic projection are repeatedly asked in RGPV Engineering Graphics exams. :contentReference[oaicite:1]{index=1}
| Topic | Repeated Pattern | Frequency |
|---|---|---|
| Projection of Lines | Line inclined to HP and VP, true length and inclinations | ⭐⭐⭐⭐⭐ |
| Projection of Planes | Pentagonal, hexagonal, rhombus and rectangular lamina | ⭐⭐⭐⭐⭐ |
| Orthographic Projection | Principles and first angle vs third angle projection | ⭐⭐⭐⭐ |
| True Length & Inclinations | Determine TL, θ and φ | ⭐⭐⭐⭐ |
| Auxiliary Planes | Auxiliary plane method and applications | ⭐⭐⭐⭐ |
| Projection of Points | Points in different quadrants | ⭐⭐⭐ |
High Chance Questions for Next Exam
- Draw projection of line AB inclined to HP and VP.
- Determine true length and true inclinations of a line.
- Draw projections of pentagonal plane inclined to HP.
- Draw projections of hexagonal lamina inclined to VP.
- Explain Orthographic Projection with neat sketch.
- Differentiate First Angle and Third Angle Projection.
- Explain Auxiliary Plane construction problems.
- Draw projections of points located in different quadrants.
Topic Weightage Analysis
| Topic | Importance |
|---|---|
| Projection of Lines | ⭐⭐⭐⭐⭐ |
| Projection of Planes | ⭐⭐⭐⭐⭐ |
| Orthographic Projection | ⭐⭐⭐⭐ |
| Auxiliary Planes | ⭐⭐⭐⭐ |
| Projection of Points | ⭐⭐⭐ |
Download Engineering Graphics Unit 2 PDFs
Download complete Unit 2 notes, important questions and PYQ analysis for RGPV Engineering Graphics exam preparation.
Download Notes PDFHow to Prepare Graphics Unit 2
- Always draw XY line first before starting projection problems.
- Practice projection of lines daily because it is the most repeated topic.
- Remember the rules of HP, VP, front view and top view clearly.
- Practice true length and true inclination problems repeatedly.
- Learn First Angle and Third Angle Projection difference table.
- Use proper construction lines and darken only final visible lines.
- Practice plane projection problems like pentagon, hexagon and rhombus.
Frequently Asked Questions
Is Engineering Graphics Unit 2 important for RGPV exams?
Yes, Unit 2 is very important because projection of lines and planes are repeatedly asked in RGPV Engineering Graphics exams.
Which topic is most important in Graphics Unit 2?
Projection of Lines, Projection of Planes and True Length & True Inclinations are the most important topics.
Are drawing questions asked from Unit 2?
Yes, Unit 2 mainly contains drawing questions from projection of points, lines and planes.
How should I prepare Unit 2 quickly?
Focus on projection of lines inclined to HP and VP, true length problems, projection of planes and first angle vs third angle projection.
Is this website official?
No, this is an independent educational website created only for student support and exam preparation.