# what is representative fraction in engineering drawing

•A plain scale consists of a line divided into suitable number of equal units. %%EOF B. stream x��Y�r7}���GBaE��� 0000001550 00000 n For an in-depth look at both engineering and architectural scales, check out this tutorial on CAD Scale Factors by ArchToolbox. Ans37:-The ratio of the drawing size of an object to its actual size is called the Representative fraction. 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. Diagonal Scale_Problem 1 . Explanation: Enlarging scale means that the drawing is drawn with the bigger dimensions in comparison to the actual dimensions of the object. 0000002135 00000 n Enabling Objectives 1) You will be able to identify the difference between engineer (civil) and architect scales. 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�|? @���͑Ie`T�����III) �'Q` ���@��� here the ratio called representative factor is more than unity. is 1/5000 or 1: 5000. The actual length of the object / Length of an object in the drawing B. Isometric length of the object / Length of an object in the drawing C. Length of an object in the drawing / Actual length of the object D. Length of an object in the drawing / … 0000000716 00000 n T *��l!ִ���&Facc�TZZX�`(�0����@��Ʀ��[�f'0�\$�@M-,w�.gY 6F����A�a���L������0�M|a��. trailer ME 111: Engineering Drawing Lecture 3 05-08-2011 SCALES AND Engineering Curves Indian Institute of Technology Guwahati Guwahati – 781039. <<07C7FB82A6EAEF478A2F1A442701E4AA>]>> Representative Factor or Scale Factor = (in same units) Case1: RF will be given directly as a ratio or as a fraction. 1. a) What is a Representative Fraction? 0000011920 00000 n ; RF = 1: 20,000 RF = 1 Explanation: Representative fraction is the ratio of the length of the object represented on drawing to the actual length of the object represented. 180 0 obj<>stream 0000001374 00000 n 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� 16 0 obj What is the type of scale in which the representative fraction is 1:1? or scale factor (S.F.)? To draw a scale, need to know the “Representative Factor (RF)”. representative fraction (r.f. other rfs are described as 1:10, 1:100, 1:1000, 1:1,00,000 scales 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.. 0 Reading engineering drawings requires knowledge of the following elements: Scales; Symbols; Projections; Lines; How to Interpret Scales in Engineering Drawings. ... ISOMETRIC DRAWINGS. Q37 – What is the representative fraction (R.F.) 0000011648 00000 n Or it is also called Scale factor. Scales on Drawing Sheet i) Representative fraction … <> 23 0 obj Q38 – What are the main uses of scale? 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. Engineering Drawing is one of the basic courses to study for all engineering disciplines. 3. These plans, made by the steel fabricator, are assembly drawings for the steel structure: A line of 1 meter is shown by 1cm on a scale. R.F. Type of scales. (������8�)5t�Nd�7�rc Q37 – What is the representative fraction (R.F.) 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��; ��! 160 21 8 0 obj 0000018016 00000 n 2) Using a scale, you will be able to measure objects shown on civil engineering plans and architectural R.F. Definition of representative fraction : a map scale in which figures representing units (as centimeters, inches, or feet) are expressed in the form of the fraction 1/ x (as 1/250,000) or of the ratio 1: x to indicate that one unit on the map represents x units (as 250,000 centimeters) on the earth's surface 2. use following formulas for the calculations in this topic. 0000015190 00000 n Representative Fraction - The Ratio of length of the drawing to the actual length of the object represented is called Representative Fraction (R.F). 0000015891 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. Complete Idea of Isometric View and Isometric Projection. endobj or scale factor (S.F.)? .
When a 1 cm long line in a drawing represents 1 metre length of the object,
length to be measured in cm. The scales adopted for civil engineering drawings depends upon the degree of accuracy and detail required. scales in engineering 1. for full size scale r.f.=1 or ( 1:1 ) means drawing & object are of same size. Representative Fraction (RF) - Fractional Scale - Ratio Scale: Therefore, the representative fraction (R.F.) )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. Fraction Scale: The scale is also expressed by means of a vulgar fraction whose numerator is invariable unity. Representative Fraction The scale of a drawing is indicated by a ratio, called the Representative Fraction (RF) or Scale Factor. 0000002825 00000 n = Dimension of an object on sheet / Actual dimension of an object Q38 – What are the main uses of scale? 17 0 obj = Dimension of an object on sheet / Actual dimension of an object. endobj 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. Representative fraction (R.F.) x�b```a``��|��������x\$��"l�d�\$���!�fɮ|cҽc����ׇ��s7"��c�{�gE��t�2930�1��1��:3;��֙�%|��f�e�G�"�&�6#��q�Ж�© 6X�l+PYKf[l�Q��sbA�� �90]��쒮a� �AF���T��IE The distance between two places is 240km and its equivalent distance on map is 12cm. %PDF-1.3 6. If the distance of 300 km is presented as 15 cm on the map find representative fraction. So Engineering drawing is a starting point of all engineering branches such as Mechanical, Production, Civil, Electrical, Electronics, Computer science, Chemical etc. b) Define Eccentricity c) Discuss the areas where engineering drawing can be applied. 0000003334 00000 n A. area of drawing v actual area volume as per drwg. the drawing is five times bigger than the actual object. Scales: Representative fraction. - R.F. 1:50000 can be shown as 1/50000 as well. stream 0000002035 00000 n 0000001670 00000 n Engineering Drawing is one of the basic courses to study for all engineering disciplines. Plain and diagonal scale. Ans37:-The ratio of the drawing size of an object to its actual size is called the Representative fraction. 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. 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. 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 Draw plain scale & indicate 270 km and 120 km. startxref Ans38 – The following are the main uses of scale in engineering practice. Engineering drawing is a graphical language of an engineer to convey one’s ideas most effectively, easily, conveniently and with high speed. 598 0000003961 00000 n <> 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. E.g. If the scale were If the scale were 0000015428 00000 n When a 1 cm long line in a drawing represents 1 x max. So if you plan a route with a total distance of 22cm on the map, that would imply that you'll be traveling (22cm x 500m) / 1cm = 11000m or 11km on the ground. There is a ‘Representative fraction’ (RF) and it is defined as? 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. Reading engineering drawings requires knowledge of the following elements: Scales; Symbols; Projections; Lines; How to Interpret Scales in Engineering Drawings. Definition A scale is defined as the ratio of the linear ... Representative fraction (R.F.) 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. There is a ‘Representative fraction’ (RF) and it is defined as? ���ʮ��91�@y 6NR�?�4�����6Y*X7�����>3��ș�#��q> �C4�x�C6n.���1R#l�O����홌-w���̛�d��rT�2���4���}:�@��>���٧. C. Graphical scale : 0000015776 00000 n 9 0 obj Winter – 2014 (Old) 8. 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 D. 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. = = = xcm cm m cm R F. Plain scale. 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. Take the value to find the length of the scale. 72 108 120 150 ‘Representative fraction’ (RF) is defined as. endobj 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. Ans37:-The ratio of the drawing size of an object to its actual size is called the Representative fraction. :�_�ËtN�'�-%�&���������ۨI��N �ÿq��,:�_�D�+g��h�����bqZ�����b��T蜔��謜�W�endstream area of drawing v actual area volume as per drwg. Plain scale construction in engineering drawing - Duration: 20:39. Its Representative fraction (RF) is This list includes abbreviations common to the vocabulary of people who work with engineering drawings in the manufacture and inspection of parts and assemblies. 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. ‘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 A. a) Enlarged scale b) Reduced scale c) Full size scale d) Graphical scale View Answer 0000003521 00000 n R.F. ... Engineering Drawing by ND Bhatt. Hence the scale is enlarging scale. b length of scale (in cm) = r.f. K���Tމ}�d��;�4��4���wq��H�EE� %�쏢 This means, 1 cm on the drawing represents 10 m on the ground, the scale of the map is 10 m to 1 cm. 6. Define representative fraction. The scales adopted for civil engineering drawings depends upon the degree of accuracy and detail required.
6. Engineering drawing abbreviations and symbols are used to communicate and detail the characteristics of an engineering drawing. 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. %PDF-1.4 %���� stream 160 0 obj <> endobj The actual length of the object / Length of an object in the drawing B. Isometric length of the object / Length of an object in the drawing C. Length of an object in the drawing / Actual length of the object D. Length of an object in the drawing / … This set of Engineering Drawing Multiple Choice Questions & Answers (MCQs) focuses on “Types of Scales – 1”. A representative fraction of 1:0.2 means 5:1, i.e. xref When a 1 cm long line in a drawing represents 1 meter length of the object, 100 1 1 100 1 1 1 . 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. A representative fraction (RF) is the ratio of distance on the map to distance on the ground. Plain Scale_Problem 2 . Summer – … Understanding Scale and Representative Fraction . is A) Cubic centimeter B) Square centimeter C) Centimeter D) None of … is less than unity is drawn on reduced scale, if greater than unity enlarging scale, if equal to one full scale. A. The fraction is called “Representative Fraction” or RF. Importance of Engineering Drawing. 0000001276 00000 n Easiest way to calculate RF(Representative Fraction ) in hindi. 0000000016 00000 n 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 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. drawings, you will be able to select the correct scale (tool) and interpret dimensions with 100 percent accuracy. 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 Scale of 1 cm = 50 m, 1 cm on the map represents 50 m (5000 cm) on the ground. Length of a line in the drawing RF =-----Actual length of the line on the object The terms ‘scale’ and ‘RF’ are synonymous. =���#��o�e`N��G�\$!�xq(d�u�Cڐ�G-n���⤣6f���������&�q �.�����mz��D?m����}a��I���06 Plain Scale_Problem 1 . The units will be listed on the map, such as 1 inch or 1 centimeter. 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. = Dimension of an object on sheet / Actual dimension of an object 0000004348 00000 n The first unit is subdivided into smaller parts. 0000001417 00000 n <> ... (W07)
Representative Fraction
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