D46 FACE THE CHALLENGE

Assertion (A): M20 grade concrete is used for RCC works. Reason (R): M20 has low tensile strength.

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

Answer explanation

M20 is used in RCC; however, tensile strength is not the reason for its use.

Assertion (A): Slump test indicates workability of concrete. Reason (R): High slump means stiffer concrete.

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

Answer explanation

Slump test is for workability, but higher slump means more fluid, not stiffer.

Which of the following is NOT a component of a suspension bridge?

• Main cable
• Suspender
• Truss
• Well foundation

Answer explanation

Well foundation is used for piers, not specific to suspension bridges.

The main function of weep holes in retaining walls is to:

• Drain water
• Support masonry
• Increase strength
• Reinforce concrete

Answer explanation

Weep holes release hydrostatic pressure behind retaining walls.

In reinforced concrete, the main role of reinforcement is to resist:

• Compression
• Shear
• Tension
• All of the above

Answer explanation

Concrete is weak in tension; steel handles tension forces.

Bernoulli's equation is based on the assumption that the fluid is:

• Non-viscous
• Compressible
• Highly turbulent
• Non-inertial

Answer explanation

Bernoulli's equation assumes incompressible, non-viscous, steady flow.

Which among these is a pozzolanic material?

• Cement
• Clay
• Silica fume
• Sand

Answer explanation

Silica fume reacts with calcium hydroxide to form additional C-S-H gel.

The unit of kinematic viscosity is:

• m²/s
• m/s
• m³/s
• N·s/m²

Answer explanation

Kinematic viscosity is ν = μ/ρ, with unit m²/s.

For canal lining, the most common material used is:

• Brick
• Concrete
• Bitumen
• Stone

Answer explanation

Concrete is widely used for lining due to durability and low seepage.

The type of bar used in corners of rectangular stirrups is:

• Cranked bar
• L-bar
• Bent-up bar
• Hook bar

Answer explanation

L-bar fits the 90° corner shape in stirrups for corner anchorage.