Question

The eye of the observer should be ____________ above while taking a reading using a ruler.

Answer 1

Answer:

There should be no angle other than 90° between the point of visibility and the scale. Any change in direction of the person taking the readings can make the person to see some other reading which is above or below the actual reading and can result in errors.

Answer 2

Explanation:

In such conditions the eyes of the observer should be study and straight in front of the scale. There should be no angle other than 90° between the point of visibility and the scale.