Q1: The instrument which is used in plane tabling for obtaining horizontal and vertical distances directly without resorting to chaining, is known as

ANS:B - telescopic alidade

I think the answer is telescopic alidade. As it helps us to sight both horizontal and vertical objects easily and it measures vertical angles from which we can measure vertical and horizontal distances is using trigonometric equations. The correct answer is telescopic alidade (option B) because when we do a plane table survey with the help of plane alidade we have to measure horizontal distances with tape or chain on the ground and then we plot them on our sheet with whatever scale we have choosen.

Hence, the correct answer should be option B. Telescopic alidade as option C and B we can directly eliminate. Option B is correct because plan alidade is used for sighting the objects and drawing the rays towards the objects.

While Telescope alidade is used for the horizontal distance between the instrument and point sighted.