Question

How will you determine the zero-error ofa screw-gauge?

ICSE Class 9 Physics Chapter Measurements and Experimentation

Answer 1

If the zero of the main scale does not coincide with zero of circular scale, the micrometer is said to have zero-error. It may be of two types:
(i) Positive zero-error: If the zero line of circular scale is below the base line of the main scale, then the zero-error is said to be positive and the correction is negative.
(ii)Negative zero-error:If the zero line of circular scale is above the base line of the main scale, then the zero-error is said to be negative and the correction is positive