GATE CE Mock Test 1 (20 Questions, Free)
A free GATE Civil Engineering mock test with 20 original questions on mechanics, structures, RCC, soils, fluids, hydrology, environmental and transportation.
This mock test has 20 original GATE-style questions across the civil engineering syllabus. Give yourself 60 minutes, write your answers on paper, then open each question to check. Score +1 per correct answer and −1/3 per wrong MCQ.
Solid mechanics and structures
A steel bar 2 m long with area 500 mm² carries an axial load of 50 kN. E = 200 GPa. What is its elongation in mm?
Show answer and explanation
Answer: 1δ = PL/(AE) = 50000 × 2000 / (500 × 200000) = 1 mm.
A rectangular beam 200 mm wide and 300 mm deep carries a bending moment of 18 kN·m. What is the maximum bending stress in MPa?
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Answer: 6Section modulus Z = bd²/6 = 200 × 300²/6 = 3 × 10⁶ mm³; σ = M/Z = 18 × 10⁶ / 3 × 10⁶ = 6 MPa.
A column fixed at both ends has actual length L. Its effective length for Euler buckling is:
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Answer: DBoth ends fixed: L_e = L/2. (Fixed–free is 2L, pinned–pinned is L, fixed–pinned about 0.7L.)
A simply supported beam of span 4 m carries a central point load of 20 kN. What is the maximum bending moment in kN·m?
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Answer: 20M_max = PL/4 = 20 × 4/4 = 20 kN·m.
Which of these increase the deflection of a cantilever with an end load? (Select all that apply.)
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Answer: A, Bδ = PL³/(3EI): it grows with L and with smaller E. A deeper section raises I and reduces deflection.
Concrete and steel
For Fe 415 steel, the limiting neutral axis depth ratio x_u,max/d is:
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Answer: BPer IS 456, x_u,max/d is 0.53 for Fe 250, 0.48 for Fe 415 and 0.46 for Fe 500.
A slab carries a dead load of 4 kN/m² and a live load of 3 kN/m². What is the factored design load in kN/m² (load factor 1.5)?
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Answer: 10.5w_u = 1.5 × (4 + 3) = 10.5 kN/m².
Geotechnical engineering
A saturated soil has water content 30% and specific gravity 2.7. What is its void ratio?
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Answer: 0.81Se = wG with S = 1: e = 0.30 × 2.7 = 0.81.
At a depth, total stress is 150 kPa and pore water pressure is 50 kPa. What is the effective stress in kPa?
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Answer: 100σ' = σ − u = 150 − 50 = 100 kPa.
For a sand with φ = 30° and no cohesion, what is the active earth pressure coefficient? (Give 3 decimal places.)
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Answer: 0.333K_a = (1 − sin 30°)/(1 + sin 30°) = 0.5/1.5 = 1/3.
Fluid mechanics and hydrology
Water flows through a pipe of area 0.02 m² at 3 m/s and then through a section of area 0.01 m². What is the velocity there in m/s?
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Answer: 6Continuity: A₁V₁ = A₂V₂, so V₂ = 0.02 × 3/0.01 = 6 m/s.
A pipe of diameter 0.1 m carries water at 0.02 m/s. ν = 1 × 10⁻⁶ m²/s. What is the Reynolds number?
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Answer: 2000Re = VD/ν = 0.02 × 0.1/10⁻⁶ = 2000.
Flow in an open channel has velocity 3 m/s and depth 0.4 m. Taking g = 10 m/s², the flow is:
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Answer: CFr = V/√(gy) = 3/√(10 × 0.4) = 3/2 = 1.5 > 1, so the flow is supercritical.
A crop has a base period of 120 days and duty 864 ha/cumec. What is its delta in metres?
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Answer: 1.2Δ = 8.64 B/D = 8.64 × 120/864 = 1.2 m.
Environmental and transportation
A sedimentation tank of volume 600 m³ treats 200 m³/h. What is the detention time in hours?
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Answer: 3Detention time = V/Q = 600/200 = 3 hours.
The 5-day BOD of a waste is 200 mg/L and the rate constant (base e) is 0.23 per day. What is the ultimate BOD in mg/L? (Round to the nearest integer.)
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Answer: 293L₀ = BOD₅/(1 − e^(−kt)) = 200/(1 − e^(−1.15)) = 200/0.683 ≈ 293 mg/L.
A vehicle moves at 20 m/s. Reaction time is 2.5 s and f = 0.4; take g = 10 m/s². What is the stopping sight distance in m?
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Answer: 100SSD = vt + v²/(2gf) = 50 + 400/8 = 50 + 50 = 100 m.
On a curve of radius 100 m with a design speed of 20 m/s, e + f must equal (g = 10 m/s²):
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Answer: 0.4e + f = v²/(gR) = 400/1000 = 0.4.
On a map of scale 1 : 500, two points are 4 cm apart. What is the ground distance in metres?
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Answer: 204 cm × 500 = 2000 cm = 20 m.
In surveying, a closed traverse is used to:
Show answer and explanation
Answer: AIn a closed traverse the latitudes and departures must sum to zero; the closing error measures how accurate the work was.
Your score
| Score (out of 20) | What it means |
|---|---|
| 16 and above | Strong: move to full-length papers |
| 10 – 15 | Revise the subjects where you lost marks |
| Below 10 | Go back to the lessons, then retake after two weeks |
Revise with the formula sheet and follow the study plan.