3. A light house of 120 m height is just visible above the horizon from a ship. The correct distance (m) between the ship and the light house considering combined correction for curvature and refraction, is
4. While deriving an expression for loss of head due to a sudden expansion in a pipe, in addition to the continuity and impulse-momentum equations, one of the following assumptions is made :
Options
A. Head loss due to friction is equal to the head loss in eddying motion
B. The mean pressure in eddying fluid is equal to the downstream pressure
C. The mean pressure in eddying fluid is equal to the upstream pressure
10. A prestressed concrete rectangular beam of size 300 mm x 900 mm is prestressed with an initial prestressing force of 700 kN at an eccentricity of 350 mm at midspan. Stress at top of the beam due to prestress alone, in N/mm2 is