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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 30 s . The length of the pendulum is measured by using a meter scale of least count 1 m m and the value obtained is 55.0 c m . The percentage error in the determination of g is close to

Options

  1. A0.2 %
  2. B6.8 %
  3. C3.5 %
  4. D0.7 %

Correct answer

B. 6.8 %

Step-by-step solution

g = 4 π 2 l T 2 ∆ g g = ∆ l l + 2 ∆ T T = 0.1 55 + 2 × 1 30 = 0.06848 Percentage error ≈ 6.8 %

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