1. Strength of Materials (SOM)
Core Formulas
Stress = P / A
Strain = ΔL / L
Hooke’s Law → σ = Eε
Elongation:
→ ΔL = (PL / AE)
Bending
Bending Equation → M/I = σ/y = E/R
Max BM (Important):
UDL → wL² / 8
Point Load (center) → WL / 4
⚡ Shortcuts
Max BM in simply supported beam = mid-span
Shear force changes sign → BM is max/min
Area under SFD = BMD
⚠️ Trap
Units mismatch (N/mm² vs kN/m²) → common mistake
2. Fluid Mechanics
Core Formulas
Continuity → A₁V₁ = A₂V₂
Bernoulli → P/γ + V²/2g + z = constant
Reynolds Number → Re = ρVD/μ
⚡ Flow Type
Re < 2000 → Laminar
Re > 4000 → Turbulent
Head Loss
Darcy-Weisbach →
→ hf = fL V² / (2gD)
⚡ Shortcuts
Velocity ↑ → Pressure ↓ (Bernoulli)
Smaller area → higher velocity
3. Concrete Technology
Core Concepts
W/C Ratio:
↓ W/C → ↑ Strength
Ideal → 0.4 – 0.6
Tests
Slump → Workability
Compaction Factor → Low workability
Vicat → Consistency
⚡ Shortcuts
More water = weak concrete
Vibration = compaction
⚠️ Trap
Slump ≠ strength (students confuse this)
4. Soil Mechanics
Key Formulas
Void Ratio → e = Vv / Vs
Porosity → n = Vv / V
Unit Weight → γ = W / V
Permeability
Unit → m/s
⚡ Shortcuts
Sand → High permeability
Clay → Low permeability + high cohesion
Shear Strength
τ = c + σ tanφ
5. Structural Analysis
Basics
Determinate → solvable by equilibrium
Indeterminate → need compatibility
Important
Simply supported beam → 0 indeterminacy
Fixed beam → 3
⚡ Shortcut
Count reactions vs equations:
If reactions > equations → indeterminate
6. Surveying
Core Formula
RL = HI – FS
Key Terms
BM → fixed reference level
BS → Back sight
FS → Fore sight
⚡ Shortcut
Always move BM → BS → IS → FS
⚠️ Trap
Sign errors in leveling
7. Environmental Engineering
Key Concepts
pH:
<7 → Acidic
7 → Basic
BOD:
High BOD → more pollution
⚡ Shortcut
Clean water = Low BOD
8. Transportation Engineering
Important
Camber → drainage
Super elevation → curves
Traffic
Unit → PCU
⚡ Shortcut
More speed → more centrifugal force → need banking
9. CPM & PERT
Formulas
PERT Time →
→ (to + 4tm + tp) / 6
Standard Deviation →
→ (tp – to) / 6
Concepts
Critical Path → Longest path
Float (critical) = 0
⚡ Shortcut
Delay in critical path = delay in project
10. Engineering Mathematics (Quick Revision)
Must Know
Derivative:
x² → 2x
sinx → cosx
Integration:
∫dx = x
Log
log₁₀(100) = 2
⚡ Shortcut
% Trick:
25% = divide by 4
50% = divide by 2
11. Exam Killer Shortcuts
Time Strategy
1st round → Easy questions
2nd → Medium
Last → Tough
Smart Guessing
Eliminate 2 wrong → 50% chance
Numerical Hack
Check units & options → eliminate fast
⚠️ Most Common Mistakes (Avoid These)
❌ Ignoring units
❌ Mixing formulas (especially SOM & FM)
❌ Over-attempting tough numericals early
❌ Not revising formulas daily
1-Day Before Exam Strategy
Revise only formulas
Solve 20–30 mixed MCQs
Avoid new topics
Sleep properly