Q. At a small water treatment plant which has 4 filters, the rates of filtration and backwashing are 200 m3/d/m2 and 1000 m3/d/m2, respectively. Backwashing is done for 15 min per day. The maturation, which occurs initially as the filter is put back into service after cleaning, takes 30 min. It is proposed to recover […]
Q. A coal containing 2% sulfur is burned completely to ash in a brick kiln at a rate of 30 kg/min. The sulfur content in the ash was found to be 6% of the initial amount of sulfur present in the coal fed to the brick kiln. The molecular weights of S, H and O
Q. A flocculation tank contains 1800 m3 of water, which is mixed using paddles at an average velocity gradient G of 100/s. The water temperature and the corresponding dynamic viscosity are 30oC and 0.798×10-3 Ns/m2, respectively. The theoretical power required to achieve the stated value of G (in kW, up to two decimal places) is
Q. The total rainfall in a catchment of area 1000 km2, during a 6 h storm, is 19 cm. The surface runoff due to this storm computed from triangular direct runoff hydrograph is 1×108 m3. The Φindex for this storm (in cm/h, up to one decimal place) is Ans: 1.5 Sol:
Q. A three-fluid system (immiscible) is connected to a vacuum pump. The specific gravity values of the fluids (S1, S2) are given in the figure. The gauge pressure value (in kN/m2, up to two decimal places) of 𝑝1 is Ans: -9.0 – -8.0 Sol:
Q. A group of nine piles in a 3 × 3 square pattern is embedded in a soil strata comprising dense sand underlying recently filled clay layer, as shown in the figure. The perimeter of an individual pile is 126 cm. The size of pile group is 240 cm × 240 cm. The recently filled
Q. The total horizontal and vertical stresses at a point X in a saturated sandy medium are 170 kPa and 300 kPa, respectively. The static pore-water pressure is 30 kPa. At failure, the excess pore-water pressure is measured to be 94.50 kPa, and the shear stresses on the vertical and horizontal planes passing through the
Q. A cable PQ of length 25 m is supported at two ends at the same level as shown in the figure. The horizontal distance between the supports is 20 m. A point load of 150 kN is applied at point R which divides it into two equal parts. Neglecting the self-weight of the cable,
Q. A 6 m long simply-supported beam is prestressed as shown in the figure. The beam carries a uniformly distributed load of 6 kN/m over its entire span. If the effective flexural rigidity EI = 2×104 kNm2 and the effective prestressing force is 200 kN, the net increase in length of the prestressing cable (in
A 6 m long simply-supported beam is prestressed as shown in the figure Read More »
Q. A level instrument at a height of 1.320 m has been placed at a station having a Reduced Level (RL) of 112.565 m. The instrument reads -2.835 m on a levelling staff held at the bottom of a bridge deck. The RL (in m) of the bottom of the bridge deck is (A) 116.720
