A. entrance locks are provided with massive gates
B. the locks of dock gate are operated by means of heavy bascule bridges and connected machinery
C. minimum required depth of water for the vessels is maintained
D. all the above

A. 125vm
B. 180 m
C. 100 m
D. 150 m

A. is the end of the road at the harbor
B. may be protected by break water walls
C. is a protected area of water where boats can move safely
D. None of them

A. facilities are provided for receiving cargo and passengers
B. port buildings are constructed for commercial purposes
C. A. ships get shelter and protection against destructive forces due to sea waves
D. all the above

A.  compressive force due to collapse of the wave
B. direct compressive force due to its horizontal component
C. shear force due to deflected vertical force
D. all of the above

A. the rising tropical air flows towards the polar region in the upper strata
B. the surface gets heated more effectively than the arctic areas
C. after heating, the air becomes lighter and is displaced by cool air from the polar regions
D. all of the above

A. change in the density of air
B. difference in temperature over the surface of the earth
C. both (a) and (b)
D. None of them

A. pressure head
B. velocity head
C. the sum of elevation
D. all of the above

A. is a current perpendicular to the shore line caused due to wind.
B. is a current parallel to the shore, caused due to tangential component of the wind
C.  is the raised line of sand, parallel to the sea coast
D. is the slow movement of surface water at sea caused by the wind

A. the fathom line of 5 m depth
B. the coast line attacked by the waves.
C. the fathom line of 10 m depth
D. the swell of the sea breaking on the shore or reefs