181. If f is the focal length, t is the angle of tilt, then the distance of isocentre on the

principal linefromthe principal point is f tan t/2

182. Parallax bar is used to measure parallax difference

183. As compared to mirror stereoscope, lens stereoscope is small in size

184. Setting out of bridges involves determination of length of centre line,position of piers

185.Boning rod-It is generally used in layout of trenches for sewers, pipe lines etc Travelling rod-The horizontal piece can be moved along a graduated vertical staff Sight rails-The horizontal, member of the cross head nailed to the posts Batter boards-It is a flat, square,wooden board which is forced on the top of a pin anchored in ground. It is also known as slope rail.

186. In triangulation, the best shape of the triangle would be

isosceles with two base angles of 56° 14' each

187.Fathometer-Sounding instrument Passometer-Distance measuring instrument Tellurometer-Microwave instrument Altimeter-Height measuring instrument

188. A closed compass traverse PQRS is run with a prismatic compass in a clock-wise direction:

The value of the included angle S is

-260°

189.The vertices of an would include: zenith, pole & heavenly body

190. The tilt displacement in an aerial photograph is radial from

isocentre point

191 Adjustment of surveying instruments-Bringing the various fixed parts of the instrument into proper relation with one another Bowditch rule-Balancing the latitudes and departures Triangulation-Measuring all the angles and the base line Bessel's method-Solution of 3-point problem

192. If a quantity A has a weight of 3, then the weight of A/3 will be 27

193. In a parabolic vertical curve, the rising grade g₁ = +0.80percentage and the falling grade g₂ = -0.70%. The rate of change of grade is 0.05 per chain. The length of the vertical curve is 30 chains

194. Which one of the following indicates the correct relationship between the flying height (H), the focal length (f), the air base (B) and the photographic base (b)? B = BH/f

195.While measuring horizontal angles by the method of repetition with a theodolite, readings are taken on both the verniers. Which one of the following errors will be eliminated by reading both the verniers?

Error due to eccentricity of the centres

196. An angle-measuring instrument reading upto one-sixth of a degree on the main scale is equipped with a vernier having 19 main scale divisions divided into 20 parts. The correct least count for the instrument is 30 seconds

197. It is required to produce a small-scale map of an area in a magnetic zone by directly plotting and checking the work in the field itself. Which one of the following surveys will be most appropriate for this purpose? Plane Table

198

Clinometer-Angle measuring instrument Pantograph-Plan enlarging instrument Tellurometer-Microwave instrument Ghat tracer-Gradient finding instrument

199. A 30 m metric chain is found to be 0.1 m too short throughout the measurement. If the distance measured is recorded as 300

m, then the actual distance will be 299.0 m

200. Offsets are lateral measurements made with respect to main survey lines