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Units and Measurements physics ncert solutions class 11th Physics Class 11th Physics NCERT Exemplar Solutions Class 11th Chapter Two

Time for 20 oscillations of a pendulum is measured as t1= 39.6 s; t 2= 39.9 s; t 3= 39.5 s. What is the precision in the measurements? What is the accuracy of the measurement?

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Payal Gupta | Contributor-Level 10

3 months ago

This is a short answer type question as classified in NCERT Exemplar

t₁=39.6s, t₂=39.9s and t₃=39.5s

Least count of measuring instrument =0.1s

Precision in the measurement =least count of the measuring instrument =0.1s

So mean value of 20 observation

Mean value of t= $\frac{t_{1} + t_{2} + t_{3}}{3} = \frac{39.6 + 39.9 + 39.5}{3} = 39.7 s$

Absolute error in

t₁= t-t₁ = 39.7-39.6 =0.1s

In t₂= t-t₂= 39.7-39.9=-0.2s

In t₃= t-t₁= 39.7-39.5= 0.2s

Mean error = $\frac{0.1 + 0.2 + 0.2}{3} = 0.17 s \approx 0.2$

Accuracy in the measurement = $? 0.2 s$

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Time for 20 oscillations of a pendulum is measured as t1= 39.6 s; t 2= 39.9 s; t 3= 39.5 s. What is the precision in the measurements? What is the accuracy of the measurement?

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