engineering graphics
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ENGINEERING GRAPHICS,EG,GRAPHICS,ENGINEERING DRAWING,EG QUESTION BANK, IMPORTANT QUESTIONTRANSCRIPT
DEPARTMENT OF MECHANICAL ENGINEERING
ENGINEERING GRAPHICS
TWO MARKS Q&A
UNIT I PLANE CURVES AND FREE HAND SKETCHING
Conic sections:
1. When the cutting plane is perpendicular to the axis of the cone, the curve of
intersection obtained is a CIRLE
2. When the cutting plane is passing through the apex and base of the cone, the curve of
intersection obtained is an ISOSCELES TRIANGLE.
3. When the cutting plane is inclined to the axis of the cone, the curve of intersection
obtained is an ELLIPSE.
4. When the cutting plane is inclined to the axis of the cone and parallel to a generated,
the curve of intersection obtained is a PARABOLA.
5. When the cutting plane is inclined at a axis very small angle with the axis or parallel
to the axis, the curve of intersection obtained is an HYPERBOLA
6. Define Eccentricity:
A conic is defined as the locus of a point which moves in a plane, in such a way
that the ratio of its distance from the focus to its distance from the directrix is always
a constant .This constant ratio is called as eccentricity and is represented by letter “e”
Eccentricity e = Distance of the moving point from focus Distance of the moving point from directrix
7. Ellipse:
An ellipse is also defined as a plain curve generated by a point which moves in
such a way that, at any position the sum of its distance from two fixed points is
always a constant .The fixed points are called as foci and the constant is equal to the
major axis of the ellipse.
UNIT II PROJECTION OF POINTS, LINES AND PLANE SURFACES
1. Define the term projection.
The image of an object to the plane.
2. What are the different types of projections?
Based on number of views:
Orthographic projections (2D)
Pictorial projections (3D)
Based on number of views:
Projections Points
Projections of straight line
Projections of plane
Projections of solid
3. Define the term Horizontal Plane
A plane which is located in horizontal direction is called as Horizontal Plane (HP)
4. Define the term Vertical Plane.
A plane which is located in vertical direction is called as Vertical Plane (VP)
5. Define reference line.
It is the intersecting line of the HP and the VP at right angles
6. What are the types of quadrants?
First, Second, Third and fourth quadrant.
7. What is the location of the first quadrant?
Above the HP and In front of the VP
8. What is the location of the second quadrant?
Above the HP and behind the VP
9. What is the location of the third quadrant?
Below the HP and behind the VP
10. What is the location of the fourth quadrant?
Below the HP and In front of the VP
11. Define front view (Elevation)
The view direction is parallel to the HP and perpendicular to the VP.
12. Define top view (Plan).
The view direction is parallel to the VP and perpendicular to the HP.
13. Show the comparison chart for the projections of points
S. No
Quadrant
With respect to point’s data
With respect to XY line
HP VP Front ViewTop
View
1 I Above In front Above Below
2 II Above Behind Above Above
3 III Below Behind Below Above
4 IV Below In front Below Below
Projections of Straight line
14. Define the term straight line.
It is the shortest route to join any two points.
15. What are the different positions of a straight line?
Parallel to both the HP and the VP
Parallel to the HP and perpendicular to the VP
Parallel to the VP and perpendicular to the HP
Inclined to the HP and Parallel to the VP
Inclined to the VP and Parallel to the HP
Inclined to both the HP and the VP
16. Define the term True Length.
The actual length of the straight line is called as TL.
17. Define traces of a straight line.
A point of intersection of the line with the HP and the VP.
18. Define Horizontal Traces (HT) of a straight line.
A point of intersection of the line with the HP.
19. Define Vertical Traces (VT) of a straight line.
A pint of intersection of the line with VP.
20. Give the different notations for the projections of straight line.
True Length (TL) = a’ b1’
Apparent Front View (AFV) = a’b’
Apparent Top View (ATV) = ab
True inclination (angle) with the HP = ø
21. What are all the conditions of Traces can be obtained in a straight line.
Inclined to the HP and Parallel to the VP only HT no VT
Inclined to the VP and Parallel to the HP only VT no HT
Inclined to both the HP and the VP both HT and VT
22. What are all the conditions of Traces can’t be obtained in a straight line?
Parallel to both the HP and the VP here no HT and VT
23. What are the different methods used in the projections of straight line?
Rotating line method (all kinds of problems)
Rotating Trapezoidal plane method (only for determine TL)
Auxiliary inclined Plane method (AIP)
24. Define the plane.
It is a two dimensional object having length, breadth only. Here thickness can be
neglected (t= 0)
25. What are different conditions of the plane?
Surface is Perpendicular to the HP and parallel to the VP
Surface is Perpendicular to the VP and parallel to the HP
Surface is Perpendicular to both the HP and the VP
Surface is inclined to the HP and Perpendicular to the VP
Surface is inclined to the VP and Perpendicular to the HP
Surface is inclined to both the HP and the VP
26. What are the different types of lamina?
Square, rectangular, Triangular, Pentagon, Hexagon and Circle
UNIT-III PROJECTIONS OF SOLIDS
27. Define the term solid.
It is a 3 dimensional object having length, breadth and thickness (height)
28. What are the different types solids?
According to Physical appearance:
Polydehra
Prisms,
Pyramids
Special solid (Cube)
Solids of revolution
Cylinder
Cone
Special solid (Sphere)
29. What are the different types of prism and pyramid?
Prism: Pyramid:
Square SquareRectangular RectangularTriangular TriangularPentagon PentagonHexagon Hexagon
30. What is meant by horizontal solid?
A solid which is kept at horizontal position, then it is called as horizontal solid.
31. What is meant by vertical solid?
A solid which is kept at vertical position, then it is called as vertical solid.
32. What is meant by oblique solid?
A solid has its axis inclined to its base (HP), when it rests on the HP on its base.
33. Define frustum of the solid.
A sectional plane is parallel to the base (HP) and perpendicular to the axis of the solid and removes the upper portion.
39. Define truncated solid.
A sectional plane inclined to the base and on removing the upper portions of the solid.
40. Give the examples for frustum and truncated solids.
Dustbin = Frustum of a cone (Sectional Shape = Circle)
Artificial water cane = Truncated of a cylinder (Sectional shape = Ellipse)
41. What are the positions of the solids?
Axis perpendicular to the HP and parallel to the VP
Axis perpendicular to the VP and parallel to the HP
Axis parallel to both the HP and the VP
Axis inclined to the HP and parallel to the VP
Axis inclined to the VP and parallel to the HP
Axis inclined to both the HP and the VP
42. Give the true shape of the different positions of the straight-line.
S. No Condition of the straight line True shape
1Axis perpendicular to the HP and
parallel to the VPTop View (Plan)
2Axis perpendicular to the VP and
parallel to the HPFront View (Elevation)
3Axis parallel to both the HP and the
VPSide View
4Axis inclined to the HP and parallel
to the VP
First project Top View
(Plan)
5Axis inclined to the VP and parallel
to the HPFirst project Front View
(Elevation)
6Axis inclined to both the HP and
the VP ----
UNIT- IV SECTIONS OF SOLIDS
43. What is meant by section of solids?
When an object has more invisible details and complicated shape, a section plane or
cutting plane may be assumed suitably, to cut the object, As a result of cutting, a
portion which is usually of the smaller size, between the observer and the cutting
plane is assumed to be removed.. This process is known as section of solids.
44. What are the various positions of the cutting plane?
The positions of cutting planes are:
Cutting plane perpendicular to HP and parallel to VP.
Cutting plane perpendicular to VP and parallel to HP.
Cutting plane perpendicular to both HP and VP.
Cutting plane inclined to HP and perpendicular VP.
Cutting plane inclined to VP and perpendicular to HP
45. How to represent the cutting plane?
The cutting plane or section plane is always represented by their traces
46. What is meant by sectional view?
The cutting plane is an imaginary plane. The view of an object with cut portion is
projected on to a reference plane and is known as the sectional view.
47. How to observe cut portion when projected on to a reference plane?
The cut portion is observed as a straight line when it is projected on to a reference
plane to which the cutting plane is perpendicular.
48. What is true shape of section & how it is obtained?
The actual shape of the cut portion is known as true shape of section. It is projected
and obtained in a principle reference plane or auxiliary plane which is parallel to the
cutting plane.
49. What is apparent section?
In a view where the cut portion is not seen as its true shape is known as apparent
section.
50. How to represent true shape of section or apparent section?
The cut portion projected and obtained in the apparent section or true shape of section
is represented by uniformly spaced hatched lines. These hatched lines are
approximately inclined at 450 to the principle outer lines. They have a uniform space 2
to 3 mm between them.
51. How to obtain the true shape of section?
When a cutting plane cuts a solid, the cut portion is removed and the section with new
corners or points is obtained on the sides or edges of the solid. These points are
obtained in the projection and joined in proper sequence to draw the section in that
view.
52. Mention the basic shape of true shape of following solids?
True shape of the prism = The basic shape of the base of prism with different size.
True shape of the pyramid = The basic shape of the base of pyramid with different
size.
True shape of cone & cylinder = The elliptical shape.
53. What are the items to be included in the solution of the particular solid under
sectioning?
The solution gives i.The cutting plane with particular angle which is mentioned in the
question, ii) Sectional top view, iii) Front view and iv) the true shape of the section.
Development of surfaces
54. What is meant by development of surfaces?
The surface (faces and bases) of an object which is opened out and laid on a flat plane
is called as the development of surfaces of that object.
55. How to develop the square prism?
Its faces are seen as four rectangles of same size and two square bases.
56. How to develop the square pyramid?
Its faces are seen as four triangles of same size and shape, the base is a square.
57. In which fields the development of surfaces is involved very much?
The knowledge in development of surfaces is required in sheet metal work to make
funnel, hopper, etc., like the thin metal sheet, chimney, boiler shell and so on from
thick metal sheet. To fabricate these objects, the development of the object is drawn
on the metal sheet, then cut and folded to form the required object.
58. What is meant by double curved surfaces?
A surface generated by revolving a curved surface about a straight line in a plane is a
double curved surface. Double curved and warped surfaces such as sphere, ellipsoid,
etc., are developed approximately.
59. What are the single curved surfaces?
Cylinders and cones.
60. Mention the methods used to draw development of surfaces?
Parallel line method
Radial line method
Zone method
Lune method
Triangulation method.
61. Explain the procedure of parallel line method to develop the surfaces?
The parallel line method is used to draw development of prisms & cylinders. In this
method two stretch-out lines whose length is equal to the base circumference
(perimeter) are drawn parallel to each other with the gap between them is equal to the
axis length or height of the solid and the faces are marked on it. The bases are also
opened out and drawn in an arbitrary position.
62. Explain the procedure of Radial line method to develop the surfaces?
The radial line method is used to draw development of pyramids & cones. In this
method, an arc is drawn with the radius equal to the true length of the slant edge of a
pyramid or the generator of a cone, to get the development of the surfaces.
63. Explain the Zone method to develop the surfaces?
The zone method is an approximate method to draw the development of a sphere. In
this method, the sphere is cut into many slices(zones) and they have the approximate
shape of a frustum of a cone. These frustums are developed to get the development of
the sphere.
64. Explain the Lune method to develop the surfaces?
The lune method is also an approximate method that is used to draw the development
of a sphere. In this method, the sphere is cut into many lunes, and jointed to get the
sphere.
65. Explain the Triangulation method to develop the surfaces?
The triangulation method is used to draw the development of transition pieces. A solid
with bottom and top bases of dissimilar and different shapes is called as a transition
piece. For example, consider a transition piece of bottom base, a square and top base,
a circle. It is developed by imagining the surfaces consisting of many triangles.
66. Mention the procedure for finding the subtended angle?
Subtended angle θ = (r/R) x 3600
Where r = base circle radius in mm
R = true length of generator in mm
UNIT -V ISOMETRIC AND PERSPECTIVE PROJECTIONS
67. What is meant by pictorial projection?
Pictorial views show all the three dimensions of an object which are useful to
understand, about that object.
68. What are the various types of pictorial projection?
i. Isometric projection
ii. Oblique projection
iii. Perspective projection
69. Mention the use of Isometric & Oblique projections?
Isometric & Oblique projections are commonly used to prepare the pictorial view of
smaller objects and they are commonly used in Mechanical, Production, Automobile,
Aerospace and Chemical Engineering to show the machine components.
70. Mention the use of Perspective projections?
Perspective projection is commonly used to prepare the pictorial view of larger
objects and commonly used in Architecture and Civil engineering. The picture drawn
in perspective drawings can be compared with the photographic picture of an object
taken using camera. In perspective projection, the picture of the object is obtained in a
plane known as the picture plane by assuming that the view is taken from a specific
point known as the station point.
71. What is the relation between isometric length & true length?
Isometric length = 0.82 * true length.
72. Explain about isometric scale.
In isometric projection, the true length may be converted in to isometric length, by
multiplying it with 0.82. But the graphical conversion scales are recommended for the
accurate conversion. The diagram showing the conversion of true lengths into
isometric lengths is called as Isometric scale.
73. Explain the principle of isometric projection.
In isometric projection, isometric lengths (0.82 * true length) are always used to
prepare the drawing. Isometric projection of an object is usually drawn using the
orthographic projection which is drawn using isometric scale. It can be drawn directly
by multiplying 0.82 with lengths of all the edges.
74. Explain about the isometric view.
In isometric view, true lengths are used to prepare the drawing, neglecting the
foreshortened lengths of all edges of the object. The overall size of the isometric view
of an object is 22.5% ((1/0.81649)=1.225) larger than the isometric projection. The
method of drawing isometric view is same as isometric projection. The isometric view
is also known as isometric drawing,
75. What are the methods used to draw isometric view/ isometric projection.
The following two methods are used to draw the isometric view/ isometric projection
of an object using the orthographic projections
i) Box method
ii) Co-ordinate method.
76. Explain about box method
1. A rectangular or square box of suitable size is used to enclose the object in suach a
way that some of the corners or edges touch the box sides.
2. Draw the isometric projection/ view of the box using the isometric axes.
3. Then mark the corners of the object with reference to the box sides and corners by
measuring their distances from the orthographic projections
4. Join the visible edges of the object by drawing dark lines to complete the
isometric projection/ view. This method is commonly used.
77. Explain about Co-ordinate method?
1. The corners of the object are marked in isometric projection/ view by considering
their co-ordinates or offsets from the isometric axes or isometric line which lies in the
same isometric plane.
2. Join and show the visible edges to complete the isometric projection/ view by
drawing dark lines.
78. What shape is the isometric view of circle & what are the methods used to draw
it?
The isometric view of circle is an ellipse, and it is drawn using two methods
i) Method of point’s ii) Four-centre method.
PERSPECTIVE PROJECTION
79. What is the various perspective elements used to draw the perspective view?
The reference planes, their positions, the positions of the observer and various
perspective elements which help to draw the perspective view of an object are listed
below i) Ground plane ii) Station point iii) Ground plane iv) Ground line v) Horizon
plane vi) Horizon line etc.,
80. Define the terms Ground plane, Picture plane, Horizon plane, central plane,
Auxiliary ground plane.
Ground plane (GP): This is a horizontal reference plane on which the object for
which the perspective drawing is to be obtained is placed.
Picture plane (PP): This is a vertical reference plane. The perspective view is
obtained on this plane when the object is viewed from the station point. It is usually
placed between the object and the station point. The front view of the object is
assumed to be projected on it, if necessary. To draw the perspective drawing.
Horizon plane (HP): This is also a horizontal reference plane which is parallel to GP
and passing through the station point.
Central plane (CP): This is also a vertical reference plane, passing through the
station point and perpendicular to both GP and PP (also perpendicular to HP and
AGP)
Auxiliary ground plane (AGP): This is also an imaginary horizontal reference plane
which is parallel to GP and HP but is placed above the station point. The top view of
the object is assumed to be projected on it when drawing the perspective view.
81. Define the terms, Station point, Ground line, Horizon line, Axis of vision, Visual
rays
Station point (SP): The view point from which the object is viewed to get the
perspective drawing is called as the station point. The observer’s eye is considered as
the station point.
Ground line (GL): The vertical picture plane and the horizontal ground plane
intersect each other in a straight line which is known as the ground line.
Horizon line (HL): The vertical picture plane and horizon plane intersect each other
at right angles in a straight line and is called as horizon line.
Axis of vision (AV): A line passing through the station point and perpendicular to the
picture plane is called the axis of vision or perpendicular axis.
Visual rays: These are imaginary lines drawn to join various corners of the object to
the station point (SP) which pierce the picture plane. These piercing points are marked
in top view and are projected to front view to get the perspective projection of an
object.
82. Mention the types of perspectives.
There are two types of perspective which are commonly used,
i) Parallel perspective or One point perspective
ii) Angular perspective or Two point perspective
83. Define Parallel perspective.
When an object is positioned in such a way that one of the principle faces (eg., base or
face of a solid) is parallel to the picture plane, the perspective view obtained is called
as Parallel perspective or One point perspective
84. Define Angular perspective.
When an object is positioned in such a way that the principle faces are inclined to the
plane, the perspective view obtained is called as Angular perspective or Two point
perspective.
85. Mention the methods used to draw the perspective projection/view.
i) Visual ray method
ii) Vanishing point method
86. Explain the procedure of visual ray method?
In visual ray method, the top view and front view (or side view) of the object and
position of the station point(SP) in both the views are located. Then visual rays from
SP connecting various corners of the object in top and front views are drawn. The
piercing points of these ray with picture plane are marked in top and projected to
front view to get perspective projection of the object.
PRACTICAL APPLICATIONS
Ellipse:
Ellipse curve are used in the construction of bridges, dams, arches, pressure vessels,
manhole in boilers, stuffing boxes, glands and the reflectors used in auto mobiles
Parabola:
Parabolic curves are used in the construction of bridges arches, road sections,
parabolic reflectors, the trajectory of thrown object or missile, wall brackets, radial drilling
machine.
Hyperbola:
It is used in design of channels, cooling towers.
Cycloid:
Cycloid curves are used in the design of gear tooth profiles and the design of
conveyer for mould boxes in foundry shops.
Epic clod:
It is used in the design of profiles of gear tooth system.
Hypocycloid:
It is used in the design of profiles of gear tooth system, design of flat disk cam profile
for metal cutting machine tools
In volute:
Gear tooth profile, involutes shape in cam, impeller of the centrifugal pump.