A chemist needs to weigh samples close to with a percentage uncertainty not exceeding
PHYSICS · Multi-part · CBSE · Physics · Units and Measurements · Units and Measurements
Problem
A chemist needs to weigh samples close to 120g with a percentage uncertainty not exceeding 1.0%. The absolute uncertainty in a mass reading is taken to be half the least count of the balance being used.
Answer the following.
(i) Derive an inequality relating the least count LC of the balance to the target percentage uncertainty for a 120g sample.
(ii) Calculate the largest permissible value of LC that will satisfy the chemist’s requirement.
(iii) Express the mass 120g to the minimum number of significant figures that would be justified when using a balance with this least count.