What is the primary structural purpose of providing hooks at the ends of steel reinforcement bars in RCC members?

According to IS 456:2000, the minimum percentage of high yield strength deformed (HYSD) bars in an R.C. slab compared with total gross concrete area is:

As per standard civil engineering provisions (IS 456), the nominal clear cover (in mm) to main reinforcement bars in footings, columns, beams, and slabs are respectively:

The effect due to temperature fluctuations and shrinkage in concrete can be ignored in the design calculation for an ordinary building, whose lateral dimensions do NOT exceed:

The distance of the centroid of compressive force from the extreme compression fibre in limit state design is:

A column has an effective length of 4000 mm. Its cross-sectional size is 300 mm × 400 mm. Identify the column classification as per IS 456.

The lap length for direct tension should NOT be less than:

The depth of the neutral axis of a reinforced concrete beam section is determined by equating:

If a reinforced concrete slab has an effective depth of 90 mm, then according to IS 456, the maximum spacing permitted for the main reinforcing bars in the slab is: