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QJEEM20Ph2c2a: JEE Main 2020 Physics - Class 11 JEEM20Ph2c2a Solution: The radius of gyration of a uniform rod of length , about an…

The radius of gyration of a uniform rod of length ll , about an axis passing through a point l4{l \over 4} away from the centre of the rod, and perpendicular to it, is :

Multiple Choice Options

  • A 18l{1 \over 8}l
  • B 14l{1 \over 4}l
  • C 748l\sqrt {{7 \over {48}}} l
  • D 38l\sqrt {{3 \over 8}} l

Step-by-Step Verified Solution

JEE Main 2020 (Online) 7th January Morning Slot Physics - Rotational Motion Question 144 English Explanation

I = Ml212+M(l4)2{{M{l^2}} \over {12}} + M{\left( {{l \over 4}} \right)^2}

⇒\Rightarrow I = 7Ml248{{7M{l^2}} \over {48}}

⇒\Rightarrow MK2 = 7Ml248{{7M{l^2}} \over {48}}

⇒\Rightarrow K = 748l\sqrt {{7 \over {48}}} l

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