11) What is the use of mechanical engineer’s scale ?
This is flat or triangular shape and used for making drawings of machines and structural parts in 1/8, 1/4, 1/2 or full size.
12) What is a Vernier Scale ?
This is used to measure very small unit with greater accuracy. It consists of a primary scale and a vernier scale.Vernier scale slides on the primary scale.
13) What is Representative Fraction ?
It is the ratio of drawing to the object. R.F=Length of the object in the drawing /Actual length of the object.
14) What is Drafting machine(Mini Drafter) ?
It is a device to do drawing work neatly and quickly.An attachment provided to move any position and may be adjusted at any required height.
15) What is a lettering ?
Lettering is the presentation of information data on a drawing.
16) Why Gothic style lettering is universally used in industry ?
Because it is more legible than other styles.
17) What are Section lines ?
Section lines are thin lines and used to show the cut surface of an object in sectional view.
18) What is a Centre line ?
Centreline is a thin line in the form long and short dashes. It indicates area of symmetrical parts, circles and path of motion.
19) Explain briefly the following lines used in Engineering drawing ?
(a)Dimension Lines (b)Extension Lines (c)Leaders
Dimension lines are the thin lines used to indicate extents and direction of dimension. These are terminated with arrowheads.
Extension lines are also thin lines and it used to indicate the termination of a dimension.
Leaders are used to direct notes or identification symbols to feature on the drawing.
20) What are Cutting Plane Lines ?
These are thick lines used to indicate the location of cutting planes in sectioning and the viewing position of removed pieces.