Test on Units and Measurements

A student measures the time period of 100 oscillations of a simple pendulum four times. The data set is 90s, 91s, 95 s and 92 s. If The minimum division in the measuring clock is 1s, then the reported mean time should be :

The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1 × 10^–3 are

Which of the following units denotes the dimensions ML² / Q², where Q denotes the electric charge ?

An experiment is performed to find the refractive index of glass using a travelling microscope. In this experiment distances are measured by