Home→ Surveying →Refraction correction________________?

As applied to staff readings, the corrections for curvature and refraction are respectively The above table shows a part of a level field book. The value of X should be__________?
If the R.L. of a B.M. is 100.00 m, the back- sight is 1.215 m and the foresight is 1.870 m, the R.L. of the forward station is__________?
The following sights are taken on a “turning point”__________?
Which of the following errors can be eliminated by taking mean of bot face observations ?
If altitude bubble is provided both on index frame as well as on telescope of a theodolite, then the instrument is levelled with reference to__________?
Theodolite is an instrument used for__________?
Which of the following errors cannot be eliminated by taking both face observations ?
In the double application of principle of reversion, the apparent error is__________?
If a tripod settles in the interval that elapses between taking a back sight reading and the following foresight reading, then the elevation of turning point will__________?
A’level line’is a__________?
The rise and fall method of levelling provides a complete check on__________?
In an internal focussing type of telescope, the lens provided is__________?
The error due to eccentricity of inner and outer axes can be eliminated by__________?
The adjustment of horizontal cross hair is required particularly when the instrument is used for__________?
The cross hairs in the surveying telescope are placed__________?
Which of the following errors is not eliminated by the method of repetition of horizontal angle measurement ?
For which of the following permanent adjustments of theodolite, the spire test is used ?
If the lower clamp screw is tightened and upper clamp screw is loosened, the theodolite may be rotated__________?
Size of a theodolite is specified by__________?
A telescope is said to be inverted if its__________?
Which of the following is not the function of levelling head ?
The process of turning the telescope about the vertical axis in horizontal plane is known as__________?
The graduations in prismatic compass__________?
If the magnetic bearing of the sun at a place at noon in southern hemisphere is 167°, the magnetic declination at that place is__________?
Agate cap is fitted with a__________?
A negative declination shows that the magnetic meridian is to the__________?
The prismatic compass and surveyor’s compass__________?
Local attraction in compass surveying may exist due to__________?
The horizontal angle between the true meridian and magnetic meridian at a place is called__________?
In the quadrantal bearing system, a whole circle bearing of 293° 30′ can be expressed as__________?
In the prismatic compass__________?
For accurate work, the steel band should always be used in preference to chain because the steel band__________?
Select the incorrect statement?
The maximum tolerance in a 20 m chain is__________?
The length of a chain is measured from__________?
If the true bearing of a line AB is 269° 30′, then the azimuth of the line AB is__________?
For a line AB__________?
Which of the following is not used in measuring perpendicular offsets ?
Cross staff is an instrument used for__________?
If the length of a chain is found to be short on testing, it can be adjusted by__________?
Normal tension is that pull which__________?
The permissible error in chaining for measurement with chain on rough or hilly ground is__________?
Which of the following angles can be set out with the help of French cross staff?
The angle of intersection of the two plane mirrors of an optical square is__________?
During chaining along a straight line, the . leader of the party has 4 arrows in his hand while the follower has 6. Distance of the follower from the starting point is__________?
For a well-conditioned triangle, no angle should be less than__________?
The allowable length of an offset depends upon the__________?
Which of the following methods of offsets involves less measurement on the ground?
The correction for sag is__________?

Refraction correction________________?

A. completely eliminates curvature correction
B. partially eliminates curvature correction
C. adds to the curvature correction
D. has no effect on curvature correction

Correct Answer: partially eliminates curvature correction ✔

Last Updated: January 12, 2019