ISOMETRIC AND PERSPECTIVE PROJECTIONS
- 1.The angle between the isometric axes is
a) 180 degrees
b) 60 degrees
c) 90 degrees
d) 120 degrees
Answer: d
Explanation: Isometric projection is a type of
projection in which the three dimensions of a
solid are not only shown in one view but also
their actual sizes can be measured directly
from it. So it is needed that there exist equal
angle between the axes for easy measurement
so 360/3=120 degrees is chosen.
- 2.The value of the ratio of isometric length to
true length is
a) 0.141
b) 0.372
c) 0.815
d) 0.642
Answer: c
Explanation: If we represent a cube in
isometric view the diagonal of upper face of
cube is equal to the true length of the
diagonal. From it by drawing an actual square
around it and then calculating it gives (1/cos
30)/ (1/cos 45) =isometric /true =0.815. - 3.The length in isometric drawing of line is
20 cm. What is the true length of it?
a) 24.53 cm
b) 15.46 cm
c) 19.31 cm
d) 23.09 cm
Answer: a
Explanation: The ratio of isometric length to
true length is 0.815 so here it is given
isometric length of 20 cm. 0.815 = 20 cm /
true length => true length = 20 cm /0.815 =
24.53 cm. Every time the true length is more
than isometric length. - 4.The true length of edge of cube is 15 cm
what will be the isometric length?
a) 17.78 cm
b) 14.48 cm
c) 12.99 cm
d) 12.22 cm
Answer: d
Explanation: The ratio of isometric length to
true length is 0.815 so here it is given true
length of 15 cm. 0.815 = isometric length / 15
cm => isometric length = 15 cm x 0.815 =
12.22 cm. Every time the true length is more
than isometric length. - 5.The lines parallel to isometric axes are
called lines.
a) parallel
b) auxiliary
c) isometric
d) oblique
Answer: c
Explanation: The angle between the
isometric axes is 120 degrees if any line is
parallel to it then those are called isometric
lines. Auxiliary lines may make any angle
with horizontal and oblique is not related
here. - 6.The planes parallel to any of the two
isometric lines are called planes.
a) parallel
b) auxiliary
c) isometric
d) oblique
Answer: c
Explanation: The planes on which the faces
of cube lie if it is placed in isometric view can
be consider as the isometric planes which are
parallel to two axes of isometric view which
are x, y, z axes of isometric view. - 7.Isometric view of cube is drawn the angle
between the edge of cube and horizontal will
be
a) 15 degrees
b) 120 degrees
c) 45 degrees
d) 30 degrees
Answer: d
Explanation: Isometric view of cube is
drawn the angle between the edge of cube and
horizontal will be 30 degrees because as the
angle between the base and axis lower to will
be 90 degrees the angle between the axes is
120 degrees. 120-90 = 60 degrees.
- 8.Isometric view of cube is drawn the angle
between the edge of cube and vertical will
be
a) 15 degrees
b) 120 degrees
c) 60 degrees
d) 30 degrees
Answer: c
Explanation: Isometric view of cube is
drawn the angle between the edge of cube and
vertical will be 60 degrees because the angle
between the edge and horizontal is 30 and so
angle between vertical and horizontal is 90.
90 – 30 = 60 degrees.
- 9.The true length of line is 40 cm and
isometric view of it is drawn the length would
decrease to
a) 28.28 cm
b) 32.6 cm
c) 34.6 c
d) 38.63 cm
Answer: b
Explanation: The ratio of isometric length to
true length is 0.815 so here it is given true
length of 40 cm. 0.815 = isometric length / 40
cm => isometric length = 40 cm x 0.815 =
32.6 cm. Every time the true length is more
than isometric length. - 10.The true length of the line is 30 cm and
isometric view is drawn. How much length is
reduced?
a) 24.45 cm
b) 25.98 cm
c) 4.01 cm
d) 5.55 cm
Answer: d
Explanation: The ratio of isometric length to
true length is 0.815 so here it is given true
length of 30 cm. 0.815 = isometric length / 30
cm => isometric length = 30 cm x 0.815 =
24.45 cm. 30 cm – 24.45 cm =5.55 cm. - 11.The objects we see in nature will be in
Isometric view.
a) True
b) False
Answer: b
Explanation: The objects we watch in our
surrounds are not isometric view they are
perspective view. Isometric view is imaginary
view in which lines of sight are perpendicular
to picture plane and are parallel to each other. - 12.Isometric view of cube is drawn the angle
between the adjacent edges is
a) 90 degrees, 120 degrees
b) 60 degrees, 120 degrees
c) 120 degrees, 120 degrees
d) 90 degrees, 30 degrees
Answer: b
Explanation: Given is a cube in which the
adjacent angle are all equal and equal to 90
degrees and if isometric view is drawn then it
show front faces with angles bet between
them as 120 degrees and if take angles
between the back and front faces we get the
60 degrees. - 13.Isometric view of cube is drawn and faces
of cube are seen as
a) square
b) rectangle
c) rhombus
d) parallelogram
Answer: c
Explanation: It is given isometric view of
cube is drawn and it shows regular hexagon
in which any of the faces represent rhombus
which have diagonals cutting each other at 90
degrees any other adjacent edges have angles
between them as 60 and 120 degrees.
ISOMETRIC DRAWINGS
- 1.If isometric projection of an object is
drawn with true lengths the shape would be
same and size is how much larger than actual
isometric projection?
a) 25%
b) 29.5%
c) 22.5%
d) 33.3%
Answer: c
Explanation: If the foreshortening of the
isometric lines in an isometric projection is
disregarded and instead, the true lengths are
marked, the view obtained will be exactly of
the same shape but larger in proportion than
that obtained by the use of the isometric
scale.
- 2.If an isometric projection is drawn with
true measurements but not with isometric
scale then the drawings are called
a) Isometric projection
b) Isometric view
c) Isometric perception
d) Orthographic view
Answer: b
Explanation: Due to the ease of construction
and the advantage of measuring the
dimensions directly from the drawing, it has
become a general practice to use the true
scale instead of the isometric scale. - 3.If an isometric drawing is made use of
isometric scale then the drawings are called
a) Isometric projection
b) Isometric view
c) Isometric perception
d) Orthographic view
Answer: a
Explanation: To avoid confusion, the view
drawn with the true scale is called isometric
drawing or isometric view, while that drawn
with the use of isometric scale is called
isometric projection.
- 4.Identify the front view of the below
isometric view.
Answer: a
Explanation: Here the isometric view of
some example picture is given. Arrow in
question represents the line of sight in case of
front view from that we can get other views.
Front view is asked which can be watched
along the arrow.
- 5.Identify the top view of below isometric
view.
Answer: d
Explanation: Here the isometric view of
some example picture is given. Arrow in
question represents the line of sight in case of
front view from that we can get other views.
Top view is asked so considering the arrow
we can find top view.
- 6.Identify the side view of the below
isometric view.
Answer: b
Explanation: Here the isometric view of
some example picture is given. Arrow in
question represents the line of sight in case of
front view from that we can get other views.
Side is watched from left side or right side of
arrow placed.
- 7.Identify the side view of the below
isometric view.
Answer: c
Explanation: Here the isometric view of
some example picture is given. Arrow in
question represents the line of sight in case of
front view from that we can get other view.
Side is watched from left side or right side of
arrow placed.
ISOMETRIC DRAWING OF PLANES OR PLANE FIGURES
- 1.Front view of the square is given and has to
draw its isometric view which angle the base
has to make with horizontal?
a) 90 degrees
b) 15 degrees
c) 30 degrees
d) 60 degrees
Answer: c
Explanation: While drawing the isometric
view of any figure made of lines the base
always makes 30 degrees with horizontal and
so in square and another parallel line also
makes 30 degrees with horizontal and other
sides will be perpendicular to horizontal. - 2.Front view of the square is given and has to
draw its isometric view which angle the
vertical edge has to make with horizontal?
a) 90 degrees
b) 15 degrees
c) 30 degrees
d) 60 degrees
Answer: a
Explanation: In isometric view vertical lines
exist and make 90 degrees with the horizontal
so if the front view of a square is given and
drawn to isometric view the angle between
the vertical edge and horizontal is 90 degrees. - 3.Top view of a square is given and has to
draw its isometric view which angle the base
has to make with horizontal?
a) 90 degrees
b) 15 degrees
c) 30 degrees
d) 60 degrees
Answer: c
Explanation: While drawing the isometric
view of any figure made of lines the base
always makes 30 degrees with horizontal and
so in square and another parallel line also
makes 30 degrees with horizontal and other
sides will be perpendicular to horizontal. - 4.Top view of a square is given and has to
draw its isometric view which angle the
vertical edge has to make with horizontal?
a) 90 degrees
b) 15 degrees
c) 30 degrees
d) 60 degrees
Answer: c
Explanation: In isometric view vertical lines
exist and make 90 degrees with the horizontal
so if the top view of a square is given and
drawn to isometric view the angle between
the vertical edge and horizontal is 90 degrees.
ISOMETRIC DRAWING OF PRISMS AND PYRAMIDS
- 1.Identify the front view from the isometric
view for the below given pyramid.
Answer: b
Explanation: The isometric view should be
drawn according to the given views and in
such a way that maximum possible details are
visible. Arrow mark in the given figure show
the direction in which front is taking and
dotted lines represent hidden edges and lines.
TYPES OF PERSPECTIVE
- 1.When an object has its one or more faces
parallel to the picture plane, its perspective is
called perspective also called
one point perspective.
a) parallel
b) oblique
c) vanishing
d) angular
Answer: a
Explanation: When an object has its one or
more faces parallel to the picture plane, its
perspective is called parallel perspective also
called one point perspective as the edges
converge to a single vanishing point of the
parallel faces. - 2.When an object has its two faces inclined
to the picture plane, its perspective is called
perspective also called two point
perspectives.
a) parallel
b) oblique
c) vanishing
d) angular
Answer: d
Explanation: When an object has its two
faces inclined to the picture plane, its
perspective is called angular perspective also
called two point perspectives as the edges of
the object converge to two vanishing points. - 3.When an object has its three faces inclined
to the picture plane, its perspective is called
perspective also called 3 point perspective.
a) parallel
b) oblique
c) vanishing
d) angular
Answer: b
Explanation: When an object has its three
faces inclined to the picture plane, its
perspective is called oblique perspective also
called 3 point perspective as edges of the
object converge to three vanishing points. - 4.Vanishing points for all horizontal lines are
inclined at 45 degrees to the picture plane are
given special name of points.
a) vanishing
b) far
c) distance
d) distant
Answer: c
Explanation: Vanishing points for all
horizontal lines are inclined at 45 degrees to
the picture plane are given special name of
distance points on account of their definite
positions. They are equidistant from the
center of vision. - 5.Which are equidistant from the center of
vision?
a) Station point
b) Ground point
c) Distance point
d) Vanishing point
Answer: c
Explanation: The distance points are
equidistant from the center of vision the
distance of each from the centre of vision
being equal to the distance of the station point
from the picture plane the perspectives of all
horizontal lines inclined at 45 degrees to the
picture plane converge to a distance points on
the horizon line. - 6.The distance of which points from the
centre of vision being equal to the distance of
the station point from the picture plane?
a) Station point
b) Ground point
c) Distance point
d) Vanishing point
Answer: c
Explanation: The distance points are
equidistant from the center of vision the
distance of each from the centre of vision
being equal to the distance of the station point
from the picture plane the perspectives of all
horizontal lines inclined at 45 degrees to the
picture plane converge to a distance points on
the horizon line.
- 7.The perspectives of all horizontal lines
inclined at 45 degrees to the picture plane
converge to a points on the horizon
line.
a) vanishing
b) far
c) distance
d) distant
Answer: c
Explanation: The distance points are
equidistant from the center of vision the
distance of each from the centre of vision
being equal to the distance of the station point
from the picture plane the perspectives of all
horizontal lines inclined at 45 degrees to the
picture plane converge to a distance points on
the horizon line.
- 8.The perspective will show the object
in size when it is placed behind
the picture plane. If the object is moved
nearer the picture plane the size of the
perspective will
a) reduced, decrease
b) reduced, increase
c) increased, reduce
d) increased, increase
Answer: b
Explanation: The perspective will show the
object reduced in size when it is placed
behind the picture plane. If the object is
moved nearer the picture plane the size of the
perspective will increase and vice versa.
9.The perspective will show the object in size when it is placed in front of the picture plane. If the object is moved nearer the picture plane the size of the perspective will,
a) reduced, decrease
b) reduced, increase
c) increased, reduce
d) increased, increase
Answer: c
Explanation: The perspective will show the
object increased in size when it is placed in
front of the picture plane. If the object is
moved nearer the picture plane the size of the
perspective will reduce and vice versa.
