LIVE Course for free

Rated by 1 million+ students
Get app now
JEE MAIN 2024
JEE MAIN 2025 Foundation Course
NEET 2024 Crash Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
112 views
in General by (25.6k points)
closed by
The rise and fall method of reduction of levels, provides a check on _____.
1. back sights
2. foresights
3. both back sights and foresights
4. None of these

1 Answer

0 votes
by (30.0k points)
selected by
 
Best answer
Correct Answer - Option 3 : both back sights and foresights

i. Arithmetic check for Collimation Method:

Sum of B.S. – Sum of F.S. = last R.L. – First R.L.

ii. Arithmetic check for Rise and Fall Method:

Sum of B.S. – Sum of F. S. = Sum of rise – Sum of fall = last R. L. – first R.L.

Important Points:

Other sources of errors in levelling which are not eliminated by arithmetic checks are:

1. Instrument not correctly levelled.

2. Telescope not correctly focused.

3. The wrong crosshair reading recorded (e.g. top instead of the middle).

4. Staff incorrectly read or not held vertical.

5. Staff incorrectly booked.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...