Survey (221-240)

Updated: Apr 24, 2020

221. Given that δ denotes declination, θ the latitude of the place of observation and a the altitude of a star at the prime vertical,

sinθ = sinδ cosecα

222. Which one of the following methods estimates best the area of an irregular and curved boundary?

Simpson's method

223. The declination of a star is 21°15' N at a latitude of 43°30'N. The zenith distance at the upper culmination is 22° 15'

224. Two points A and B are 1530 m apart across a river. The reciprocal levels

measured are


The true difference in level between A and j B would be

1.545 m

225. A lighthouse is visible just above the horizon at a certain station at the sea level. The distance between the station and the lighthouse is 40 km. The height of the lighthouse is approximately 107.7

226. The true bearing of a line is 34° 20' 40" and the magnetic declination at the place of observation is 2° 00' 20" W on the date of observation. The magnetic bearing of the line is

36° 21'00"

227. Consider the following assumptions of Bowditch method:

Errors in linear measurements are proportional to √L

Correction to latitude or departure of any side

= Total error in L (or D) X Length of that side/Perimeter of traverse

228. To determine the length of a bridge proposed to be built across a wide river,

the surveying method of choice would be triangulation


229. Heliograph is a type of sun signal used in triangulation work

230. A plot of land 60 m x 20 m is measured by a steel tape. If the standard error of length and width measurements is taken as ± 1 cm, then the standard error of the area of the plot would be ±0.632 m²

231. If a 30 m length can be taped with a precision of ±0.01 m, then the standard

error in measuring 1.08 km with the same precision will be ±0.36 m

232. A 30-m steel tape was standardized at 20°C and measurements of distances were taken at 15°C. If the coefficient of linear expansion a of the material of the tape were 0.00,00112 per degree Celsius, then the error, due to temperature, per tape length would be - 0.00,00560 m

233. Which one of the following statements best defines a level surface?

A curved surface which is perpendicular to the direction of gravity at every point.

234. The area of a plot is to be determined using Simpson's rule. The following

offsets were taken to a boundary from points along a chain line, all

measurements being in metres :

12,15,22,29,36,38,31,22,17.

These were taken at 100 m intervals. Consider the following steps in this

regard

Sum of the odd ordinates = 22 + 36 +31 =89

Sum of the even ordinates = 15 + 29 + 38 + 22=104

12 + 17 = 39

Area = 100/3(39 + 2 x 89 + 4 x 104).


235. A 100 m tape is held 1 m out of line. The true length is 99.9950 m

236. In setting out a long straight line for the erection of transmission towers, it is

recommended that the forward point be set out with both face-right and face-left

with reference to the preceding point and the mean position be taken. This field

procedure eliminates die instrumental error where the line of collimation is not

perpendicular to the horizontal axis.

237. The coordinates of two end-points A and B of a traverse line AB are 90°0'00"

238. Consider the following statements regarding Plane Table surveying

It is not necessary to do accurate centering of plane table for small

scale surveys.

Compass rule may be made use of for adjusting the plane table traverse.

From the instrument station, resectors are drawn to plot the position of

objects in the field.

239.Contour gradient The line lying on the surface of the ground keeping a constant inclination to the horizontal Line of steepest gradient lying on the ground - The,gradient of the line joining the highest and the lowest point on the contour map Saddle line Line of drainage basin-The line which passes through ridges and saddles setting up a domain

240.Froude's transition-Length of curve measured on tangent with the first term only taken into account for both x & y coordinates from equation for ideal transition curve Cubic spiral-Length of curve measured on the curve itself with first term from equation for ideal transition curve taken for ycoordinate

clothoid spiral-Length of curve measured on the curve with at least two terms adopted for x & y coordinates from equation for ideal transition curve Lemniscate curve-The path actually traced by an automobile turning freely



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