Question

If the time period of oscillation of a pendulum is measured as 2.5 second using a stop watch with least count 1/2 second, then the permissible error in the measurement is

Answer 1

Here T = 2.5sec
ΔT = 0.5 sec
Percentage error in time = (ΔT / T )× 100 
= (0.5 / 2.5) × 100
= 20%