किसी बिंदु से गुजरने वाली किस प्रकार की मध्याह्न रेखा (meridian) वह रेखा होती है जिसमें उस बिंदु और उत्तरी व दक्षिणी ध्रुवों से गुजरने वाला एक समतल पृथ्वी की सतह को काटता है?

In survey work using a total station with reflector measurements, which of the following sequence of temporary adjustments must be performed at a station?

While carrying out a total station survey on one bank of a 250 m wide river, it is necessary to plot electric transmission posts on the opposite bank. No provision exists for crossing the river and the posts are inaccessible. In which mode should the survey work be done?