INTRODUCTION TO DRAWING QUESTION ANSWERS CLASS NOTES
INTRODUCTION TO DRAWING
Engineering drawing is the graphical
language of engineers. Its basics help in
reading the various types of drawings used
in the manufacture of items. Question
answers on engineering drawing increases
the understanding and knowledge. This
helps to draw various types of practical
drawings. In engineering drawing,
lettering plays an important role. It
explains certain parts which cannot be
shown by lines or curves. A poor writing
mars the appearance of a drawing.
Lettering is talk of drawing. It should be
simple, easy, uniform and legible. Different
proportions are used in different
situations. Use reduced and enlarged scales
for large and small objects. Full scale is
used for objects whose dimensions are
manageable on the drawing sheet.
Dimensions are very important for a
drawing. Without dimensions, it is not
possible to know the size and shape of the
object. Without dimensions, an object
cannot be manufactured.
Q1 – What is lettering?
The art of writing the alphabets A, B, C,…….Z and numbers such as 0,1, 2, 3…… is lettering.
Q2 – What are the main requirements of lettering?
1) The knowledge of shape and proportion of each letter.
2) The knowledge of the order and direction of the strokes used in making letters.
3) The knowledge of the general composition of letters.
4. The knowledge of the rules for combing letters into words and words into sentences.
5. The knowledge of writing letters in plain and simmer manner. It is done with free hand and speed.
Q3– What do you mean by composition of letters?
Ans3 – The composition means the composing of letters into words and words into sentences. Arrangement in which open area between two letters of a word appears equal to the eye.
Q4 – What do you mean by uniformity of letters?
Ans 4 – The uniformity of lettering means keeping same
(iv) Strength of lines of letters
It is very essential for good lettering in engineering drawing.
Q5 – What do you mean by normal, compressed and extended lettering?
(a) Normal lettering
The normal lettering has normal height and width and are used for general purposes. The width of the normal letter is about 0.67 times of the height of the letter.
(b) Compressed lettering
The compressed lettering is writing letters in the narrow space. Space limitation use compressed letter writing. The width of the condensed letters is much less than height as compared with normal lettering.
(c) Extended lettering
The extended lettering is that which is much wider than normal letters but with same height.
Q6 – What are the guidelines and why are these necessary in lettering?
Ans6:- The guidelines regulate the height and inclination to the letters and numerals. The guidelines are necessary to maintain the uniformity of the letters.
7. What are a single and a double stroke letters?
A letter written in one stroke of the pencil is a single stroke letter.
Further, a letter written in two strokes of the pencil is a double stroke letter.
8 Describe types of lettering.
Letter writing in drawing is of great importance. It can be single, double stroke, Gothic and Roman.
These be written with H*B or H* grade pencil.
Q9 – What do you mean by single stroke letters and what are its types?
Letters can be single and double stroke.
Single stroke letters means that the thickness of the line of the letter should be such as is obtained in one stroke of the pencil.
Single stroke letters are of two types.
2) Inclined (minimum 800 With horizontal)
Q10 – What is the Gothic and Roman lettering?
Gothic lettering – The lettering in which all the alphabets are of uniform width or uniform thickness is known as Gothic lettering. It can be divided into following groups.
(i) Vertical/ upright Gothic lettering
(ii) Inclined or Italic Gothic lettering
Roman lettering – The lettering in which all the alphabets are composed of thick and thin elements is known as roman lettering and can either be vertical or inclined.
Q11 – What do you mean by freehand lettering?
The art of writing the alphabets without the use of drawing instrument is called freehand lettering. The freehand lettering is of the following types.
(a) Vertical or upright freehand Gothic lettering.
(i) Single stroke vertical freehand Gothic lettering.
(ii) Lowercase vertical freehand Gothic lettering.
(b) Inclined or italic freehand Gothic lettering.
(i) Single stroke italic freehand Gothic lettering.
(ii) Lower case italic freehand Gothic lettering.
Q 12 – What should be the grade of pencil used for lettering?
HB and H grade pencils, sharpened to a conical point, should be used for lettering.
Q13. Discuss size of letters.
Size of letter means height of letters. As per ISI, sizes are as given in the table.
Height of alphabets in mm
6, 8,10 and 12
3, 4, 5 and 6
Notes such as materials, legends and dimensions
2, 3, 4 and 5
Q14. Define engineering drawing. Why drawing is called universal language of engineers?
Engineering drawing is a graphical language of an engineer. It conveys one’s ideas most effectively, easily, conveniently and fast. Engineering drawing is a starting point for all engineering branches. It is spoken, read, and written in its own way. Engineering drawing has its own grammar in terms of projections. It has conventional representations & types of lines. There are abbreviations, symbols and various geometric constructions.
Q15. Name different drawing instruments..
Drawing board, drawing sheet, mini-drafter, scale, pencil and sand paper block, cello-tape, eraser and compass.
Q16. What are the standard sizes of drawing sheets according to I.S.I. and which is suitable for drawing work?
The standard size of sheets according to I.S.I. are
A0 (1189 X 841),
A1 (841 X 594),
A2 (594 X 420),
A3 (420 X 297),
A4 (297 X 210) and
A5 (210 X 148).
Drawing sheet of size 594 X 420 i.e. A2 size is generally used by engineering students as it is very handy and easy for drawing work in class.
Q17. What are the ways of sharpening a pencil for good and accurate work? Which type of pencil is more suitable for drawing work?
There are two ways of sharpening a pencil
(i) a small piece of sand paper of zero grade, pasted upon a piece of wood.
Q18. Why cello-tape is used instead of drawing pins, nowadays?
Nowadays, cello tapes are used in place of drawing pins for its practical convenience as the drafter,
can be moved easily over the tape and the drawing board is spoiled by the use of drawing pins.
Q19. What is layout of drawing sheet?
(i) Leave the following margins
From the top 1 cm
on bottom, 1 cm
From right 1 cm
on left, 3 cm
(i) Make a title block(rectangle) of size 65 mm high and 185 mm width on the right bottom side for title block, parts list
Q20. Why is the layout of sheet is necessary?
Layout of the drawing on the drawing sheet is necessary in order to make its reading easy and fast.
The title blocks, parts list will provide all the required information.
Q21. List out the contents of title block.
The title block should contain the following information.
(i) Name of the institution
(ii) Title of drawing
(iii) Name, Branch, section and Roll no. of the student
(iv) Type of scale used
(v) Drawing number
(vi) Type of symbol for the method of projection
Q22. What do you mean by convention/ code?
The representation of any matter by some standard sign or symbol on the drawing is known as convention or code. The conventions make the drawing simple and easy to draw.
Q23. What do you understand by thickness of lines?
There are three distinct thickness of lines used in engineering drawing. These lines are specified as thick, medium and thin lines. A thick line is 3 times thicker than thin line. A medium line is 2 times thicker than a thin line.
Q24. What is a scale?
A scale by which we keep same or reduce or increase the actual size of the object on a drawing.
Scale = Size taken on the drawing / Actual size
Q25. Discuss various types of scales in a drawing.
There are three types of scales.
1) Full size scale
Full size scale uses actual measurements of the object.
For example 1:1
2) Reducing scale
Reducing scale uses shorter than actual measurements of the object. For example 1:4
3) Enlarging scale
Enlarge scale uses larger measurements than actual dimensions of the object. For example 2:1.
Q26. What is the representative fraction (R.F.) or scale factor (S.F.)?
The ratio of the size on drawing to its actual size is Representative fraction.
R.F. = Dimension of an object on the drawing sheet / Actual dimension of an object
For example 1/10.
Q27. What are the main uses of scale?
Ans – The following are the main uses of scale in engineering practice.
(i) The scales prepare reduced or enlarged size drawings.
(ii) The scales set off dimensions.
(iii) The scales measure distances directly.
Q28. What are the information necessary for scale?
Ans – To construct a scale, the following information is necessary.
(i) The representative fraction (R.F.) of the scale.
(ii) The units used.
(ii) The maximum length of the scale
Q29. What is difference between a plain scale and a diagonal scale?
A plain scale is a line divided into a number of equal parts. The first part is further sub-divided into smaller parts. It contains only two units (ones and tens or tens and hundred)
A diagonal scale consists of three units. For example dm, cm, and mm (ones, tens and hundreds).
Q30. What is the principle of a diagonal scale?
The principle of diagonal scale is to divide a short line into ten equal parts. It has further diagonal division into another ten parts.
Q31. Describe scale in drawing.
Depending on the size of the object, the size taken on drawing (sheet) can be same or different.
Size on drawing can be = or < or > the actual size.
If size on drawing = the actual size, it is a FULL SCALE. It represents 1:1.
If size on drawing < the actual size, it is a REDUCED SCALE, represented as 1:4
If size on drawing > the actual size, it is a ENLARGED SCALE, represented as 3:1
Q32. Give applications of scales.
Use of the scale is for the following purposes:
For drawing an object on a full, reduced and enlarged scale.
To mark dimensions on the drawing.
Q33. What are different types of scales?
Different styles of scales are:
In which, one can measure certain units and its one tenth value. For example a scale in cm and mm is a plain scale, m and dm is another plain scale.
In which, one can measure certain units, its one tenth value as well as its one hundredth value. For example a scale in m, dm and cm is a diagonal scale. A scale in dm, cm and mm is another diagonal scale.
Comparative or Corresponding scale
These are two different scales having same R.F. but different units. Place these side by side. or over one and another.
For example: in miles and kilometers.
These scales can be plain scales or diagonal scales.
Vernier scales: It is a scale which is extremely accurate for measurement. It uses a Vernier caliper. Vernier caliper is an instrument to measure a dimension very precisely. Normally its least count is 1/100 of the scale unit. Say a scale is in cm, then a Vernier can measure very accurately up to 1/100 of a cm i.e. 2.12 cm.
Q34. What are the requirements for the construction of a scale?
(i) to measure maximum distance
(ii) R.F.( representative fraction) of the scale
(iii) Units of scale i.e. mm, cm, m, km
Q35. Write the procedure for the construction of a scale.
- Write the required units i.e. km, m, cm——.
- Find the R.F. of the scale.
- Find the scale length, L
- L= (R.F.) x actual distance
- Draw a line and mark 0, 1, 2, 3, 4—— at equal distances on the right side of zero.
- Sub-divide 1 main part into 10 parts on the left side of zero.
- Mention clearly the units and sub units below the scale constructed.
Construct a scale having 2cm = 1 m. Show m and dm. It should be long enough to measure a distance of 10 m.
Units are m and dm.
R.F. = 2/100=1/50
L = (1/50) x 10 x 100=20 cm
Draw a line of 20 cm length. Divide it into 10 equal parts to represent 1 m each.
Mark zero after the first division. Then number it 1, 2, 3, ——up to 9 on the right side of zero.
Divide the first part into ten equal divisions to represent 1 decimeter each.
Mark ten points on the left side of zero.
Represent full meters on the right side and decimeters on the left side of zero. Then it can represent any required length, say 5m 7 dm.
Q36. Why the drawing is called the language of engineers?
It is because drawing helps in conveying one’s ideas in an easy, convenient
and fast manner. It also makes study simple as it uses international standard
conventions as well as symbols.
Q37. What are the standard sizes of drawing sheets and which one more suitable for drawing work?
Table: Standard Sizes of Drawing Sheets
Trimmed size in mm
Width x Length
Untrimmed size in mm
Width x Length
841 x 1189
880 x 1230
594 x 841
625 x 880
420 x 594
450 x 625
297 x 420
330 x 450
210 x 297
240 x 330
148 x 210
165 x 240
Most commonly used is sheet A1 size.
Size A0 is used by Architects and draftsmen.
Q38. What is dimensioning?
Dimensioning is the art of writing the various sizes on the finished drawing of an object.
Q39. What is the importance of dimensions?
(i) Dimensions conveys all the sizes and other necessary information to draw completely the object.
(ii) Manufacturing processes and inspection requirements need dimensions.
(iii) The dimensions also includes tolerances necessary for the correct functioning of the parts in the component assembly.