PHYSICS · Multi-part · CBSE · Physics · Units and Measurements · Units and Measurements
Problem
While measuring the length of a laboratory table, a student uses a metre scale whose least count is 1mm. The student records the result as 1.2500m.
Answer the questions below.
(i) Using the rules of significant figures, explain whether the recorded value is consistent with the precision of the metre scale.
(ii) Taking half the least count as the absolute uncertainty, calculate the percentage uncertainty that the metre scale can realistically provide for a ∼1.25m length.
(iii) Compare the calculated uncertainty with the implied precision of the reported value 1.2500m and comment on the validity of the student’s result.