11) The most popular method of construction of wall breakwaters is
a) Barge method
b) Staging method
c) Low level method
d) None of the above
12) The protective barrier constructed to enclose harbours is known as
(a) breakwater
(b) wharves
(c) jetty
(d) quay
13) Drift method of tunneling is used to construct tunnels in
a) soft grounds
b) rock
c) self supporting grounds
d) broken grounds
14) Which of the following lining material is useful for shield driven tunnels in sub aqueous regions ?
a) stone masonry
b) timber
c) cast iron
d) cement concrete
15) The minimum width of apron provided is
(a) 8 m
(b) 10 m
(c) 12 m
(d) 15 m
16) Tunnel alignment is carried out by
a) surface theodolite traverse
b) triangulation
c) compass traverse
d) aerial photography
17) Berlin’s formula for finding wavelength in metres is
(a) 1.18 t2
(b) 1.28 t2
(c) 1.36 t2
(d) 1.56 t2
where t = period in seconds
18) Which of the following is a fixed type mooring accessory ?
a) bollard
b) buoys
c) cables
d) anchors
19) The breakwaters height is ______ times the expected wave heights above the mean sea level
(a) 1.2 to 1.25
(b) 1.3 to 1.35
(c) 1.4 to 1.45
(d) 1.5 to 1.55
20) A ship is berthed in a chamber and lifted by principles of buoyancy. Such a chamber is called
a) Dry dock
b) Wet dock
c) Floating dock
d) Refuge dock