devarshi-dt-logo

Question:

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

92±5.0 s

92±1.8 s

92±2 s

92±3 s

Solution:

Sum of all observation=90+91+95+92=368
Average=368/4=92
Sum of modulus errors=2+1+3+0=6
Average error=6/4=1.5, rounded off to 2.
Final answer=(92±2) s