Question

the least count of stop watch is 0.1 sec the time of 20 oscillations of pendulum is 20 sec percentage error is in the time period ​

Answer 1

Number of oscillations n=20

Time taken =25 s

∴ Time period of oscillation T=

20

25

=1.25 s

Given :

Error in time for 20 oscillations, ΔT=0.2 s

Hence error in time for 1 oscilations, ΔT

′

=

n

0.2

= s

∴ Percentage error =

T

ΔT

×100=

20×1.25

0.2

×100=0.8 %