Rev. Notes > AS > Measuring techniques Previous Topic Measuring techniques Next Topic Topics
 Measurements Errors Random error Systematic error Uncertainty Total uncertainity in addition / subtraction Total uncertainty in multiplication and division Total uncertainty in power factor Total uncertainty in the average value of many measurements Total uncertainty in the timing experiment Total uncertainty in the timing experiment Example 1 - Calculation of uncertainty Least count Spring Balance Digital Balance Protractor Micrometer Vernier calliper Digital Ammeter Cathode Ray Osciloscope

## Total uncertainty in the timing experiment

The uncertainty in the time period of a vibrating body is found by dividing the least count of timing device by the number of vibrations. For example, the time of 30 vibrations of a simple pendulum recorded by a stopwatch accurate upto one tenth of second is 54.6 s, the period
T = (54.6 s / 30)= 1.82 s with uncertainty  (0.1 s / 30) = 0.003 s
Thus, period T is quoted as T = 1.52 ± 0.003 s

Hence, it is advisable to count large number of swings to reduce timing uncertainty.

 Yunzila Said : but we have calculated the value with the given radius then what is the need of division by 2......??? 07/12/17 12:21 PM

 Yunzila Said : why in the ans is 0.6.......??? bcz after calculation we get 1.2.....!!! 07/12/17 12:17 PM

 unknown Said : ^to calculate the radius, diameter needs to be divided by 2. thus, 1.22/2 = 0.61 02/01/15 12:33 AM

 Bilal Said : where did 0.6 come from in result 09/09/14 02:51 PM