INDIABIX Section 5- Surveying

triangle/6

A lemniscate curve between the tangents will be transitional throughout if the polar deflection angle of its apex, is

206.75 m

A sewer is laid from a manhole A to a manhole B, 250 m away along a gradient of 1 in 125. If the reduced level of the invert at A is 205.75 m and the height of the boning rod is 3 m, the reduced level of the sight rail at B, is

square root "L"

Accidental or compensating errors of length L are proportional to

glaciated region

Bergchrund is a topograhical feature in

small areas in open ground

Chain surveying is well adopted for

to indicate the accuracy of the survey work

Check lines (or proof lines) in Chain Surveying, are essentially required

a vertical cliff

Contour lines of different elevations can unite to form one line, only in the case of

all the above.

For high sensivity of the bubble tube a. a liquid of low viscosity is used b. a liquid of low surface tension is used c. the bubble space should be long d. the bubble tube should not be too narrow e. all the above.

Angles from two transit stations

For locating a distant object visible from two transit stations, the method usually preferred to, is

(L1/L)S

If L is the specified length of a tape, L1 its actual length and S the measured distance, then, the true distance is given by the formula,

making a subsidiary traverse to determine the length of a long leg

If a linear traverse follows a sharp curve round a large lake where it is difficult to have long legs, the accuracy of the traverse may be improved by

horizontal sights

If the plane table is not horizontal in a direction at right angles to the alidade, the line of sight is parallel to the fiducial edge only for

north

If the whole circle bearing of a line is 180°, its reduced bearing is

north-west quadrant

In a closed traverse, sum of south latitudes exceeds the sum of north latitudes and the sum of east departures exceeds the sum of west departures, then, the closing line will lie in

all of these.

Mistakes which may produce a very serious effect upon the final results arise due to in attention in experience carelessness all of these.

200

Number of subdivisions per metre length of a levelling staff is

four times the shift.

Perpendicular offset from a tangent to the junction of a transition curve and circular curve is equal to

1 second of arc corresponds to a displacement ratio of 1:206, 300 1 degree of arc corresponds to a displacement ratio of 1:57 the angular errors tend to propagate themselves along a traverse as the square root of the number of stations the errors arising from the linear measures tend to be roughly proportional to the lengths of the lines

Pick up the correct statement from the following

the diaphragm is placed between the eyepiece and the objective but nearer to the later

Pick up the wrong statement from the following : the diaphragm is placed between the eyepiece and the objective but nearer to the former the diaphragm is placed between the eyepiece and the objective but nearer to the later the outer component of the objective is a double-convex lens of crown glass the inner component of the objective is a flint glass, convexo-concave all the above.

elevations along a straight line

Profile levelling is usually done for determining

drawing perpendiculars with a chain

Prolongation of chain line across an obstruction in chain surveying, is done by

degree of the curve

Rankine's deflection angle in minutes is obtained by multiplying the length of the chord by

an ordinary chain

Short offsets are measured with

undulating

Subtense tacheometry is generally preferred to if ground is

the multiplying constant by cos2 θ and additive constant by cos θ.

Tacheometric formula for horizontal distances using horizontal sights can also suitable be employed for inclined sights through θ by multiplying

is aplanatic and achromatic

The Huygen's telescope eye piece

X^2/2R

The approximate formula for radial or perpendicular offsets from the tangent, is

easier along the falling gradient

The chaining on sloping ground is

sub-chord

The chord of a curve less than peg interval, is known as

traverse base

The distance between terminal points computed from a subsidiary traverse run between them, is generally known, as

intermediate sights

The line of collimation method of reduction of levels, does not provide a check on

both shimmering and horizontal refraction.

The line of sight is kept as high above ground surface as possible to minimise the error in the observed angles due to

is usually directed to examine whether a certain part is truly parallel or perpendicular to another and makes the erroneous relationship between parts evident

The method of reversal

1, 3, 2, 4, 5

The operation of resection involves the following steps 1. rough orientation of the plane table 2. the three lines form a triangle of error 3. drawing lines back through the three control points 4. select a point in the triangle of error such that each ray is 5. equally rotated either clockwise or anti clockwise 5. the points obtained by three rays is the correct location. The correct sequence is

orientation

The operation of revolving a plane table about its vertical axis so that all lines on the sheet become parallel to corresponding lines on the ground, is known

resolving power of telescope

The ratio of the distances at which a stated length can be distinguished by the telescope and the human eye, respectively, is called

2cos(triangle/2)

The ratio of the length of long chord and the tangent length of a circular curve of radius R deflecting through angle Δ, is

azimuth

The smaller horizontal angle between the true meridian and a survey line, is known

all the above.

There are two stations A and B. Which of the following statements is correct : a. the fore bearing of AB is AB b. the back bearing of AB is BA c. the fore and back bearings of AB differ by 180° d. all the above.

to a target fixed on theodolite tripod on which theodolite may be fitted easily

To avoid large centering error with very short legs, observations are generally made

manifold and correct

To orient a plane table at a point P roughly south of the mid-point of two inaccessible conical hill stations A and B in the plains, a point C is selected in line with AB and table is oriented at C by bringing ab in line with AB. A ray is then drawn towards P and at P the table is oriented by back ray method. The orientation so obtained, is

when the axes of rotation of the graduated circle and the verniers are not coincident, the instrument possesses eccentricity the mean of the readings of the two verniers gives correct reading free from the eccentricity one vernier may be used if the readings of two verniers differ by a constant

Which one of the following statements is correct ?

20 (sec θ - 1)

While measuring the distance between two points along upgrade with the help of a 20 m chain, the forward end of the chain is shifted forward through a distance

repetition

You have to observe an included angle with better accuracy than what is achievable by a vernier, you will prefer the method of

5

For indirect ranging, number of ranging rods required, is

100/n^2

Correction per chain length of 100 links along a slope having a rise of 1 unit in n horizontal units, is

radius of the curve

Designation of a curve is made by :

range and period of oscillation both vary

During secular variation of magnetic meridian at different places

30°

A well conditioned triangle has no angle less than