B.TECH LEVEL PAPER

Assertion (A): Lacing in built-up steel columns prevents buckling of individual components. Reason (R): It acts as a lateral restraint.

• Both A and R are false
• Both A and R are true but R is NOT the correct explanation of A
• A is true but R is false
• Both A and R are true and R is the correct explanation of A

Answer explanation

Lacing resists lateral buckling by tying components together.

Match List-I with List-II: A. Axel Bendixen B. Hardy Cross C. Winkler D. St. Venant 1. The mathematical theory of elasticity 2. Theory of curved bars 3. Slope-deflection method 4. Moment distribution method

• 1-2-3-4
• 3-4-2-1
• 1-2-4-3
• 3-2-4-1

Answer explanation

Bendixene deflection, Hardy Moment distribution, Winkler Curved bar, Venant Elasticity

A mild steel bar is 2m long, 25mm in diameter and is subjected to axial pull of 50kN. What is elongation? (E = 200 GPa)

• 0.81 mm
• 1.02 mm
• 0.57 mm
• 0.32 mm

Answer explanation

δ = PL/AE = 50×10³×2 / (π/4×25²×200×10⁹) = 0.57 mm

Which test is conducted to determine the permeability of soil in the laboratory?

• Triaxial Test
• Permeameter test
• Consolidation test
• Sand replacement test

Answer explanation

Permeability is measured in lab using constant or variable head permeameter.

The condition for maximum velocity in a circular channel for open channel flow is when depth is:

• 0.5 D
• 0.81 D
• 0.94 D
• 0.33 D

Answer explanation

The velocity is maximum when the depth of flow = 0.81 × diameter for circular channels.

Which one of the following statements regarding plane table survey is not correct?

• Orientation may be done by back sighting
• Two-point problem can be solved graphically
• Three-point problem can't be solved graphically
• It can be used for large scale mapping

Answer explanation

Three-point problem can be solved graphically – the statement is incorrect.

Numerical: Calculate design speed if SSD required is 80 m, reaction time is 2.5 s and deceleration 3 m/s².

• 72 km/h
• 65 km/h
• 75 km/h
• 60 km/h

Answer explanation

V = solve from SSD formula = ~72 km/h

Statement: Gusset plates are used to transfer loads from members to joints.

• Partially true
• Cannot say
• True
• False

Answer explanation

Gusset plates are load-transfer interfaces — true.

A jet of water moving with a velocity of 30 m/s strikes a stationary flat plate normally. If the flow rate is 0.05 m³/s, what is the force exerted on the plate?

• 15 N
• 30 N
• 1500 N
• 450 N

Answer explanation

Force = ρQV = 1000 × 0.05 × 30 = 1500 N (since ρ = 1000 kg/m³).

Which type of steel section has least torsional stiffness?

• Channel section
• Box section
• I-section
• T-section

Answer explanation

Channel has open shape, low torsional resistance.