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NTA Abhyas 2020

Exam: NTA Abhyas
Year: 2020
Subject: Physics
Chapter: Units and Dimensions

NTA Abhyas 2020 · Physics · Units and Dimensions

In a simple pendulum experiment for determination of acceleration...

In a simple pendulum experiment for determination of acceleration due to gravity

( g )

, time taken for

20

oscillations is measures by using a watch of

1

second least count. The mean value of time taken comes out to be

30s

. The length of the pendulum is measured by using a meter scale of least count

1

mm and the value obtained is

55.0

cm. The percentage error in the determination of

g

is close to

Options

A $\text{0.2} %$
B $\text{6.8} %$
C $\text{3.5} %$
D $\text{0.7} %$

Correct answer

B. $\text{6.8} %$

Step-by-step solution

g = \dfrac{4{\pi}^{2}l}{T2}

\dfrac{∆ g}{g} = \dfrac{∆ l}{l} + \dfrac{2 ∆ T}{T}

= \dfrac{0.1}{55} + 2 \times \left(\dfrac{1}{30}\right)<br />

= 0.06848

<br />Percentage error \approx6.8%

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