FRIDAY WEEKLY EXAM (13/06/2025)

The area of a trapezium with parallel sides 12 m and 8 m, and height 6 m is:

• 60 m²
• 100 m²
• 72 m²
• 96 m²

Answer explanation

Area = ½ × (12 + 8) × 6 = 60 m²

A rectangular beam 300 mm wide and 500 mm deep has a moment of inertia about its base equal to:

• 3.125 × 10⁸ mm⁴
• 2.604 × 10⁸ mm⁴
• 1.562 × 10⁸ mm⁴
• 1.042 × 10⁸ mm⁴

Answer explanation

I = (b × h³)/3 = (300 × 500³)/3 = 3.125 × 10⁸ mm⁴

A steel bar of 20 mm diameter and 2 m length is subjected to a tensile force of 20 kN. If E = 2×10⁵ N/mm², the elongation is:

• 0.64 mm
• 0.32 mm
• 1.27 mm
• 0.16 mm

Answer explanation

Stress = 20000 / (π/4 × 20²) ≈ 63.66 N/mm²; Elongation = (63.66 / 200000) × 2000 ≈ 0.64 mm

The volume of a circular slab of 2.5 m diameter and 0.15 m thick is:

• 0.736 m³
• 0.924 m³
• 0.589 m³
• 1.023 m³

Answer explanation

Volume = π/4 × D² × h = π/4 × 2.5² × 0.15 ≈ 0.736 m³

A cement bag weighs 50 kg. What is the volume of cement in m³? (Specific gravity of cement = 3.15)

• 0.016 m³
• 0.035 m³
• 0.025 m³
• 0.041 m³

Answer explanation

Volume = Mass / (SG × 1000) = 50 / (3.15 × 1000) ≈ 0.016 m³

The bearing of a line is N 30° E. Its back bearing is:

• S 30° W
• S 60° W
• N 60° W
• N 30° W

Answer explanation

Back bearing of N 30° E is S 30° W

A beam 6 m long is simply supported and loaded at the center with a 12 kN load. What is the maximum bending moment?

• 9 kNm
• 12 kNm
• 18 kNm
• 36 kNm

Answer explanation

M = (W × L)/4 = (12 × 6)/4 = 18 kNm

The reduced level of a point is 102.350 m and staff reading is 1.650 m. What is the height of instrument (HI)?

• 100.700 m
• 104.000 m
• 103.000 m
• 105.000 m

Answer explanation

HI = RL + Staff reading = 102.350 + 1.650 = 104.000 m

The unit weight of RCC with 20 mm aggregate is approximately:

• 22 kN/m³
• 24 kN/m³
• 25 kN/m³
• 26 kN/m³

Answer explanation

The unit weight of RCC (with 20 mm aggregate) is typically taken as 25 kN/m³ for estimation purposes.

Assertion (A): Theodolite is used to measure horizontal and vertical angles. Reason (R): It consists of a graduated circle and vernier scales.

• Both A and R are true, and R is the correct explanation
• Both A and R are true, but R is not the correct explanation
• A is true, R is false
• Both A and R are false

Answer explanation

A theodolite measures both angles. The reason correctly explains the construction.