Question

Correct position of the eye is very important for taking measurements. There might be error in the reading, if our eye is not completely in front of the mark. This error is known as___ error.

Answer 1

Parallax error arises when the reading is taken from a random angle instead of taking at any angle from the line of sight (normally). It is a non-technical (human) error in which there is a difference in the readings if the readings are taken at different angles from the line of sight. So to avoid this error we must always take the readings by positioning our sight just perpendicularly above the markings.