Question

2. A simple pendulum
completes 20 oscillations in 25
s. The time is measured with a
stop watch of least count 0.2 s.
The error in the measurement
of time is
O (a) 3.2 %
O (b) 2.4%
O (c) 1.6%
O (d) 0.8%​

Answer 1

Answer:

d -0.8%

Explanation:

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 %