Civil Engineering 2023 Paper II 50 marks Solve

Q2

(a) For a project consisting of several activities, the allotted time and the dependencies of the activities are presented below: | Activity | Duration (days) | Predecessor | | P | 5 | – | | Q | 4 | – | | R | 6 | Q | | S | 5 | P | | T | 7 | P | | U | 4 | T, R | (i) Prepare a network and mark critical path in it. (ii) Calculate Float, Earliest start, Earliest finish, Latest start and Latest finish times. (20 marks) (b) Trains of different speeds are to be run on a 2° curve on a broad gauge. The average speed of trains to be run on the track is 80 kmph. Calculate the value of equilibrium cant. Also calculate the maximum permissible speed on the track allowing the maximum cant deficiency. (15 marks) (c) (i) An aircraft flew at the altitude of 5000 m above the mean sea level. Two consecutive photographs were taken with the camera of focal length 300 mm on the flat ground having elevation of 2000 m above mean sea level. The longitudinal overlap is 65% and photograph print size is 300 mm × 300 mm. Calculate the scale of the photograph and distance between the two consecutive exposure stations. (5 marks) (ii) What is spectral reflectance curve ? Explain its significance in Remote Sensing. (10 marks)

हिंदी में प्रश्न पढ़ें

(a) विभिन्न क्रियाओं से बनी एक परियोजना के लिए क्रियाओं की आवंटित समय अवधि और पराश्रयता को नीचे दर्शाया गया है : | क्रिया | अवधि (दिन) | पूर्ववर्ती | | P | 5 | – | | Q | 4 | – | | R | 6 | Q | | S | 5 | P | | T | 7 | P | | U | 4 | T, R | (i) एक जाल का निर्माण कीजिए और उसमें कांतिक पथ को दर्शाइए। (ii) प्लव (फ्लोट), यथाशीघ्र प्रारंभ, यथाशीघ्र समाप्ति, यथाविलंबित प्रारंभ और यथाविलंबित समाप्ति समयों की गणना कीजिए। (20 अंक) (b) एक बड़ी लाइन पर 2° वक्र पर विभिन्न गति की रेलगाड़ियों को चलाया जाना है। रेलपथ पर चलाई जाने वाली रेलगाड़ियों की औसत गति 80 kmph है। संतुलन आनति (कैंट) के मान की गणना कीजिए। अधिकतम आनति न्यूनता की अनुमति के साथ रेलपथ पर अधिकतम अनुज्ञेय गति की गणना भी कीजिए। (15 अंक) (c) (i) एक वायुयान माध्य समुद्र तल से 5000 m की ऊँचाई पर उड़ा। एक समतल मैदान, जो माध्य समुद्र तल से 2000 m की ऊँचाई पर है, से एक कैमरा जिसकी फोकस दूरी 300 mm है, से दो क्रमागत तस्वीरें ली गईं। अनुदैर्ध्य अतिव्यापन 65% है एवं तस्वीर का प्रिंट आमाप 300 mm × 300 mm है। तस्वीर के स्केल की गणना कीजिए। दोनों क्रमागत उद्भासन स्टेशनों के बीच की दूरी बताइए। (5 अंक) (ii) वर्णक्रमीय परावर्तकता वक्र क्या है ? सुदूर संवेदन में इसकी सार्थकता की व्याख्या कीजिए। (10 अंक)

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How this answer will be evaluated

Approach

Solve all five sub-parts systematically, allocating time proportionally to marks: spend ~40% on part (a) network analysis (20 marks), ~30% on part (b) railway cant calculations (15 marks), ~20% on part (c)(i) photogrammetry (5 marks), and ~10% on part (c)(ii) spectral reflectance theory (10 marks). Begin with clear problem identification, show all calculations with proper units, draw neat diagrams for (a)(i) and label critical path distinctly, and conclude with practical implications for each engineering application.

Key points expected

  • For (a)(i): Construct correct AOA or AON network with proper node numbering and activity arrows; identify critical path as Q-R-U (14 days) or equivalent based on correct forward/backward pass
  • For (a)(ii): Calculate ES, EF, LS, LF for all activities and determine total float (TF = LS-ES or LF-EF) and free float correctly; show tabular presentation
  • For (b): Calculate equilibrium cant using e = GV²/127R (or e = 0.0007V²/R for BG) with V=80 kmph, R=875m (from 2° curve); calculate cant deficiency using IRC limit of 75mm for BG and find maximum permissible speed
  • For (c)(i): Calculate scale as f/(H-h) = 300mm/(5000-2000)m = 1:10,000; compute ground coverage and exposure station spacing using 65% overlap formula
  • For (c)(ii): Define spectral reflectance curve as plot of reflectance vs wavelength; explain significance for land cover classification, vegetation health monitoring, and band selection in Indian remote sensing applications (IRS/LANDSAT)

Evaluation rubric

DimensionWeightMax marksExcellentAveragePoor
Concept correctness20%10Correctly applies CPM/PERT methodology for (a), uses IRC-112 cant formulas with proper gauge constants for (b), applies photogrammetric scale and overlap principles for (c)(i), and accurately defines spectral reflectance with remote sensing applications for (c)(ii); cites relevant IRC/IS codes where applicableUses mostly correct formulas but may confuse total vs free float, or makes minor errors in cant formula application; photogrammetry scale calculation partially correct; spectral reflectance definition adequate but applications vagueFundamental conceptual errors such as treating network as PERT instead of CPM, using wrong curve radius formula, confusing flying height with altitude, or describing spectral signature instead of reflectance curve
Numerical accuracy20%10All calculations precise: critical path duration 14 days, equilibrium cant ~82mm, maximum permissible speed ~94 kmph (with 75mm deficiency), scale 1:10,000, exposure spacing 1050m; proper unit handling throughoutMinor arithmetic slips in one or two sub-parts; correct method but final answers slightly off; acceptable unit conversions but inconsistent presentationMajor calculation errors in multiple sub-parts; wrong formula substitutions; missing units or dimensional inconsistencies; order-of-magnitude errors in scale or cant values
Diagram quality20%10Neat AOA network with clear node numbering, activity arrows properly oriented, critical path boldly marked (double line or red); for (b) optional cant diagram showing rail positions; all diagrams labeled with durations and dependenciesNetwork drawn but nodes crowded or arrows crossing excessively; critical path indicated but not prominently; missing some activity labels or durationsNo network diagram for (a)(i); confusing or incorrect topology (wrong predecessors); illegible sketch; missing critical path marking entirely
Step-by-step derivation20%10Systematic forward pass (ES, EF) and backward pass (LS, LF) shown with clear node calculations; cant derivation shows substitution of R=1720/2°=875m; photogrammetry shows flying height above ground calculation before scale; all steps logically sequencedSome steps shown but skips intermediate calculations; forward/backward pass implied but not explicit; jumps from formula to answer without showing substitutionOnly final answers with no working; or working so disorganized that reasoning cannot be followed; missing essential steps like node numbering or overlap percentage application
Practical interpretation20%10Interprets float values for project crashing decisions in (a); discusses safety implications of cant deficiency for high-speed trains on Indian BG routes in (b); relates photogrammetric scale to map production for (c)(i); links spectral curves to crop monitoring, mineral exploration, or urban planning in Indian context for (c)(ii)Brief mention of practical relevance without elaboration; generic statements about project management or railway safety without specific Indian engineering contextNo interpretation of results; purely mathematical exercise without connecting to why these calculations matter for civil engineering practice in India

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