Ijmb Model Questions Vol1 2024 Physics Question 1

A student is required to determine the length of a metal rod using a vernier caliper. The caliper has a zero‑error of –0.02 cm (i.e., it reads 0.02 cm less than the true zero). The student records the following three successive readings after repositioning the rod each time: | Trial | Vernier reading (cm) | |-------|----------------------| | 1 | 12.34 | | 2 | 12.36 | | 3 | 12.33 | Using the data, the student must: a) Obtain the best estimate of the true length of the rod (to the nearest 0.01 cm). b) Calculate the percentage uncertainty of the measurement, taking the standard deviation of the three readings as the absolute uncertainty. c) Identify two possible sources of systematic error in the experiment and suggest one precaution for each.