JEE Mains · Physics · STD 11 - Oscillations
- JEE Mains 2021
- Medium
- MCQ
Time period of a simple pendulum is \(T\) inside a lift when the lift is stationary. If the lift moves upwards with an acceleration \(g / 2,\) the time period of pendulum will be
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(\sqrt{\frac{2}{3}} T\)
Step-by-step Solution
Detailed explanation
When lift is stationary
\(T =2 \pi \sqrt{\frac{ L }{ g }}\)
When lift is moving upwards \(\Rightarrow\) Pseudo force acts downwards
\(\Rightarrow g _{ eff }= g +\frac{ g }{2}=\frac{3 g }{2}\)
\(\Rightarrow\) New time period
\(T ^{4}=2 \pi \sqrt{\frac{ L }{ g _{ eff }}}=2 \pi \sqrt{\frac{2 L }{3 g }}\)
\(T ^{\prime}=\sqrt{\frac{2}{3}} T\)
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