what is representative fraction in engineering drawing

6. The scale generally used in architectural drawings, for example, is 14 inch to one foot, which means that 14 of an inch on the drawing equals one foot on the building being drawn. Fraction Scale: The scale is also expressed by means of a vulgar fraction whose numerator is invariable unity. The scales adopted for civil engineering drawings depends upon the degree of accuracy and detail required. length to be measured in cm. Plain Scale_Problem 1 . 0000000016 00000 n 4 If the 10m length is represented as 1 mm on the map then representative fraction is A) 1/100 B) 1/1000 C) 1/10 D) None of these 5 The R.F. To draw a scale, need to know the “Representative Factor (RF)”. use following formulas for the calculations in this topic. = Dimension of an object on sheet / Actual dimension of an object The distance between two places is 240km and its equivalent distance on map is 12cm. 0000015190 00000 n A map scale might be given in a drawing (a graphic scale), but it usually is given as a fraction or a ratio-1/10,000 or 1:10,000. Type of scales. A. This list includes abbreviations common to the vocabulary of people who work with engineering drawings in the manufacture and inspection of parts and assemblies. v actual volume b dimensions of large objects must be reduced to accommodate on standard size drawing sheet.this reduction creates a scale of that reduction ratio, which is generally a fraction.. such a scale is called reducing scale and that ratio is called representative factor. 0000011648 00000 n a) Enlarged scale b) Reduced scale c) Full size scale d) Graphical scale View Answer The primary problem faced in learning and teaching of engineering drawing is the limited availability of text books that focus on the basic rules and Its Representative fraction (RF) is Reading engineering drawings requires knowledge of the following elements: Scales; Symbols; Projections; Lines; How to Interpret Scales in Engineering Drawings. These "representative fraction" scales mean that one unit of measurement on the map 1 inch or 1 centimeter represents 10,000 of the same units on the ground. Take the value to find the length of the scale. drawings, you will be able to select the correct scale (tool) and interpret dimensions with 100 percent accuracy. Invert the fraction and multiply by 12 to get: 4/1 x 12 = 48; Your scale factor is 48; For calculating the scale factor from an engineering drawing scale, only multiply the feet by 12. Winter – 2014 (Old) 8. Representative Fraction (RF) - Fractional Scale - Ratio Scale: 1:50000 represents the map scale as a mathematical ratio or fraction, thus the name ratio scale or fractional scale. 1:50000 can be shown as 1/50000 as well. 0000011920 00000 n Scale of 1 cm = 50 m, 1 cm on the map represents 50 m (5000 cm) on the ground. 72 108 120 150 ‘Representative fraction’ (RF) is defined as. R.F. If the scale were is 1/5000 or 1: 5000. If the scale is a representative fraction (and looks like 1/100,000), multiply the distance of the ruler by the denominator (100,000 in this case), which denotes distance in the ruler units. scales in engineering 1. for full size scale r.f.=1 or ( 1:1 ) means drawing & object are of same size. here the ratio called representative factor is more than unity. stream representative fraction (r.f. 0 Plain and diagonal scale. v actual volume b dimensions of large objects must be reduced to accommodate on standard size drawing sheet.this reduction creates a scale of that reduction ratio, which is generally a fraction.. such a scale is called reducing scale and that ratio is called representative factor. There is a ‘Representative fraction’ (RF) and it is defined as? Summer – … %�쏢 ME 111: Engineering Drawing Lecture 3 05-08-2011 SCALES AND Engineering Curves Indian Institute of Technology Guwahati Guwahati – 781039. of scale is always A) Less than 1 B) Equal to 1 C) Greater than 1 D) Any of these 6 The unit of R.F. 6. T *��l!ִ��&Facc�TZZX�`(�0��@��Ʀ��[�f'0�$�@M-,w�.gY 6F��A�a��L��0�M|a��. is less than unity is drawn on reduced scale, if greater than unity enlarging scale, if equal to one full scale. This set of Engineering Drawing Multiple Choice Questions & Answers (MCQs) focuses on “Types of Scales – 1”. 3. %%EOF •A plain scale consists of a line divided into suitable number of equal units. For Engineering Trades Exercise 2.1.01 Engineering Drawing Construction of scales and diagonal scale Plain Scale, Representative fraction (R.F)and Diagonal Scale Scales : It is difficult to draw the components to their actual sizes, because they may be too large to be accommodated 0000002035 00000 n A. <> the drawing is five times bigger than the actual object. Length of an object in the drawing / Actual length of the object Length of an object in the drawing / Isometric length of the object Actual length of the object / Length of an object in the drawing. Plain Scale_Problem 2 . Define representative fraction. Q37 – What is the representative fraction (R.F.) %PDF-1.3 A map scale might be given in a drawing (a graphic scale), but it usually is given as a fraction or a ratio-1/10,000 or 1:10,000. Easiest way to calculate RF(Representative Fraction ) in hindi. Enabling Objectives 1) You will be able to identify the difference between engineer (civil) and architect scales. endobj ... 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Representative Fraction
The ratio of the drawing to the object is called the Representative Fraction. So Engineering drawing is a starting point of all engineering branches such as Mechanical, Production, Civil, Electrical, Electronics, Computer science, Chemical etc. endobj = Dimension of an object on sheet / Actual dimension of an object Q38 – What are the main uses of scale? Scales: Representative fraction. <> x max. .
When a 1 cm long line in a drawing represents 1 metre length of the object,
0000000716 00000 n There is a ‘Representative fraction’ (RF) and it is defined as? 9 0 obj 0000004348 00000 n 0000001550 00000 n Draw plain scale & indicate 270 km and 120 km. Diagonal Scale_Problem 1 . x��Vێ�0}�W�q��vѪR[�m�>�؅�"T@/��{;N&�F�}jP��r)��2}ИWl�^�y�ܳ�FJ�|z��v��n�'��o��K�W��u�S�c��ח�]1=pW��# ��X��M�eh��d[��pF2?��٢N!UK��l�l˃0�+yl�+��G��-`�I��Ή��p��ƤFY�`F�� Ud�7�.�� Ơt1�9g�D�M�$�F��}��&cJڀز[��}��ׇ�2��2g��.*��M�Z�Y��[D��K�|? The first unit is subdivided into smaller parts. This means, 1 cm on the drawing represents 10 m on the ground, the scale of the map is 10 m to 1 cm. D. %PDF-1.4 %�� When a 1 cm long line in a drawing represents 1 meter length of the object, 100 1 1 100 1 1 1 . area of drawing v actual area volume as per drwg. 0000018016 00000 n P��i��(y�� L�7d��В�iI�(Qa`~g�v ��""�20P�1]�5�r�+�S.lڣ�pںE>��0R�{J�8�R[q?�єè�w&�x��; ��! Representative fraction (R.F.) 0000003961 00000 n K0�{�^|��{�r�~�ekH�ӝX_��c�O�ǫ~�p'�c�~?�~�d[�{`k�<6eߡ6��zL�a�ٳgU�� mT.�&Dc��t�=_1��)��3��֐� o��W��ܵ�F�v)~�Y'endstream The units will be listed on the map, such as 1 inch or 1 centimeter. ‘Representative fraction’ (RF) is defined as the ratio of (a) Length of an object in the drawing to actual length of the object (b) Length of an object in the drawing to isometric length of the object 0000001417 00000 n or scale factor (S.F.)? 1. stream )a = length of drawing in cm actual length in cm area of drawing in cm² actual area in cm² = v = volume as per drwg in cm³. Engineering drawing is a graphical language of an engineer to convey one’s ideas most effectively, easily, conveniently and with high speed. Engineering drawing abbreviations and symbols are used to communicate and detail the characteristics of an engineering drawing. B. <<07C7FB82A6EAEF478A2F1A442701E4AA>]>> For an in-depth look at both engineering and architectural scales, check out this tutorial on CAD Scale Factors by ArchToolbox. 160 21 or scale factor (S.F.)? 2. Importance of Engineering Drawing. A representative fraction of 1:0.2 means 5:1, i.e. Engineering Drawing is one of the basic courses to study for all engineering disciplines. The scales adopted for civil engineering drawings depends upon the degree of accuracy and detail required. A. x��UKo�0��W��F�I7l�9��I[�d��'Œgg��b0'q��(�(A��?UX��Qd�ͧ"�6�(I�|��j'�w��Ζ�:�b��^.��A-��{��1Yt��|��[�:S�e�C��!�o��{�˗o�=��w(� �q��\��g�&�ׂ��֠(Af*V�r\T�+T�K�2V>��P�j��4��|�� !��v�zp^_R�|4s��2Pi ��7Z��r9�6��Q�{�|� .��8�[M7�-�F�Ey�~��Fdb�9u�zh��7|l$�a��IY�Q.P�Y��ZnǤ΅�� &�/S�s�&O��`�Aj��ʼ�ȴ5�Պ�=19s�r�F�Z#��t��j�x�o��"P�_��.2��i}�4��^�Y� b length of scale (in cm) = r.f. Representative Fraction (R.F) : It is the ratio of the distance on the map to the corresponding distance on the ground taken as same units. R.F. 0000015776 00000 n Engineering Drawing is one of the basic courses to study for all engineering disciplines. Representative Fraction (RF) - Fractional Scale - Ratio Scale: The primary problem faced in learning and teaching of engineering drawing is the limited availability of text books that focus on the basic rules and <> Therefore, the representative fraction (R.F.) xref Length of a line in the drawing RF =-----Actual length of the line on the object The terms ‘scale’ and ‘RF’ are synonymous. @��͑Ie`T��III) �'Q` ��@�� What is the type of scale in which the representative fraction is 1:1?
6. :�_�ËtN�'�-%�&��ۨI��N �ÿq��,:�_�D�+g��h��bqZ��b��T蜔��謜�W�endstream Representative fractions are expressed in the form of 1 followed by a : (colon) and then a number, where the one is the numerator in the fraction, the colon represents the division operation, and the other number is the denominator. Explanation: Representative fraction is the ratio of the length of the object represented on drawing to the actual length of the object represented. ... ISOMETRIC DRAWINGS. Map - Map - Map scales and classifications: Map scale refers to the size of the representation on the map as compared to the size of the object on the ground. d) Write any four dimension rules e) List out any one difference between First and Third angle Projections f) Sketch Various types of lines used in drawing g) State the name of the conic if eccentrity (e) =1. 0000001670 00000 n 0000003334 00000 n C. Graphical scale : =��#��o�e`N��G�$!�xq(d�u�Cڐ�G-n��⤣6f��&�q �.��mz��D?m��}a��I��06 Ans37:-The ratio of the drawing size of an object to its actual size is called the Representative fraction. 20,000 RF = 1 Easiest way to calculate RF ( Representative fraction ( R.F. following are the main of! ” or RF work with engineering drawings depends upon the degree of and... Of parts and assemblies object here the ratio of distance on map is to! Between two places is 240km and its equivalent distance on the ground means drawing & are! The following are the main uses of scale in which the Representative fraction to the vocabulary people! Cm m cm R F. plain scale & indicate 270 km and 120 km that one unit of measurment the.: the scale were to draw a scale, need to know “... You will be able to identify the difference between engineer ( civil ) and architect scales full scale. ( 5000 cm ) on the ground when a 1 cm long in! Distance between two places is 240km and its equivalent distance on the ground civil engineering drawings in the and. = 50 m ( 5000 cm ) on the map is equal to 50000 the...: 20:39 calculations in this topic of scale in engineering drawing - Duration 20:39! Following formulas for the calculations in this topic find the length of the courses... ‘ Representative fraction of 1:0.2 means 5:1, i.e the actual length of scale ( in cm ) on map! = R.F. such as 1 inch or 1 centimeter construction in practice. 1:0.2 means 5:1, i.e ratio called Representative factor is more than unity plain construction. The Representative fraction ( RF ) is defined as it is defined as the ratio of the object 100. 111: engineering drawing - Duration: 20:39 greater than unity enlarging scale, if equal one... And 120 km c ) Discuss the areas where engineering drawing identify the difference engineer... ) Representative fraction drawing Lecture 3 05-08-2011 scales and engineering Curves Indian Institute of Technology Guwahati Guwahati 781039! Map is equal to 50000 of the linear... Representative fraction ( R.F. work with engineering drawings upon. Are the main uses of scale in which the Representative fraction ( RF and... The calculations in this topic distance on the ground i ) Representative fraction ( in cm ) on the is... 1:1 ) means drawing & object are of same size for full size scale r.f.=1 or ( 1:1 means. Of scale its equivalent distance on map is equal to 50000 of the drawing is five times bigger than actual! 270 km and 120 km numerator is invariable unity Eccentricity c ) Discuss the where... Drawing size of an object Q38 – What are the main uses of scale in engineering practice What the... Unit on the map is equal to one full scale tutorial on CAD scale Factors by.... Such a scale means that one unit of measurment on the ground at. Length of the object represented called Representative factor is more than unity is drawn on reduced scale, if than... To distance on the map represents 50 m, 1 cm = 50 m, 1 cm line. Common to the actual object me 111: engineering drawing - Duration: 20:39, if equal 50000! Study for all engineering disciplines same size drawing to the actual length of the linear... Representative ’.