Surveying Multiple Choice Questions on “Hydrographic Survey – Introduction”.
1. Which of the following doesn’t describe the use of hydrographic surveying?
a) Laying an Alignment
b) Making underground investigations
c) Nautical charts for navigation
d) Establishing mean sea level
Answer: d
Clarification: Hydrographic surveying can find its use in making nautical charts for navigation, making underground investigations for construction, establishing mean sea level, determining shore line etc.
2. The process of measuring depth below the water surface is called _______
a) Sounding
b) Chaining
c) Traversing
d) Compass traversing
Answer: a
Clarification: Sounding indicates the process of measuring depth below the water surface. It involves calculation of the time travel by the sound waves. This can reduce the manual power and can have an enhanced report.
3. Which among the following can be possessed by the horizontal control?
a) Chaining
b) Triangulation
c) Theodolite
d) Compass
Answer: b
Clarification: The horizontal and vertical control can possess either triangulation or a traverse. This is considered as the preliminary survey procedure as it can be done for second or third order triangulations which can be used as a main control.
4. Transit tape is used in case of small survey.
a) False
b) True
Answer: b
Clarification: In case of small scale surveys, the triangulation will be more than required and usage of tape is preferred over it. This can have an advantage in economic perspective and also in terms of obtaining result.
5. Gauge readings are obtained after_______________
a) Compass survey
b) Chaining
c) Sounding
d) Traversing
Answer: c
Clarification: After the completion of the sounding procedure, the next step involved is figuring gauge readings. Gauge reading is taken because of the continuous change in level of water, which might affect the result of the survey.
6. Which of the following doesn’t come under the category of shore line survey?
a) Delineation of shore line
b) Location of shore details
c) Determination of the low and high water lines
d) Sounding
Answer: d
Clarification: Shore line survey involves in the delineation of shore line, location of shore details and their prominent features and in the determination of the low and high water lines for spring tides.
7. Which among the following doesn’t indicate the purpose of sounding?
a) Volume measurements
b) Nautical charts for navigation
c) Making sub-aqueous investigations
d) Measurement of area
Answer: a
Clarification: Sounding is conducted in order to make nautical charts for navigation, measurement of area which are subjected to scour and making sub-aqueous investigations which is needed to secure the information of construction.
8. What will be the salinity of the sea water if the temperature of the sea water is about 45˚C and the velocity of sound is given as 1678 m/s?
a) 314.62
b) 214.62
c) 134.62
d) 143.62
Answer: c
Clarification: From the relation, V = 1410 + 4.21*T – 0.037*T2 + 1.14*S. we can calculate the salinity content. On substitution, we get
1678 = 1410 + 4.21*45 – 0.037*452 + 1.14*S
S = 134.62.
9. Among the following, which is having more prominence while conducting sounding?
a) Labor
b) Signal
c) Sounding pole
d) Suitable climatic conditions