---
title: "Definition of meridian term"
subject: "Surveying I"
chapter: 4
key: "semester_3/surveying_i:define-meridian"
source: https://www.bctengineer.com/q/semester_3/surveying_i/define-meridian
site: BCT Engineering
---

# Definition of meridian term

Surveying I · Chapter 4: The Compass

- Asked in: 2081 Baisakh, 1 marks
- Video: [4.1 Compass Surveying: Meridians, Bearings, and Bearing Systems](https://www.youtube.com/watch?v=tec6yj80FZg) — Civil Modules
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/surveying_i/define-meridian
- Whole chapter: https://www.bctengineer.com/md/semester_3/surveying_i/chapter-4

## Question

Define meridian.

## Short answer

A meridian is the fixed reference line pointing north from which bearings are measured. It may be the true meridian (geographic north), magnetic meridian (direction of a free magnetic needle), or an arbitrary meridian chosen for a local survey.

## Answer

A **meridian** is the fixed reference direction (a line through a point towards north) from which the bearings of survey lines are measured. It may be the true meridian (towards geographic north), the magnetic meridian (direction of the freely suspended magnetic needle), or an arbitrary meridian.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is a meridian in surveying?
   A. A line of equal elevation
   B. A fixed reference direction towards north from which bearings are measured
   C. The line joining two survey stations
   D. The horizontal angle between two lines
   Answer: B. Bearings are angles measured from the meridian. (Key point: Meridian)

2. Which is NOT a type of meridian?
   A. True meridian
   B. Magnetic meridian
   C. Contour meridian
   D. Arbitrary meridian
   Answer: C. Meridians may be true, magnetic or arbitrary. (Key point: Types of meridian)

3. The magnetic meridian is the direction of:
   A. The geographic North Pole
   B. The first survey line
   C. The sun at noon
   D. A freely suspended magnetic needle
   Answer: D. The magnetic meridian is the needle's rest direction. (Key point: Magnetic meridian)

## Related in Surveying I

- [Definition of trilateration term](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Adefine-trilateration) — Surveying I, chapter 8

## Related in other subjects

- [Technology definition and change in culture](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Adefine-tech-culture-traditions) — Technology, Environment and Society, chapter 1