Question

Hlo Guys .

Question from JEE MAIN - 2018

seven identical circular planar rials , each of mass M and radius R are welded symmetrically as shown. the movement of inertia of the arrangement about the axis normal to the plane and passing through the point P is :

(a) 19/2 MR² (b) 55/2MR²
(c) 73/2MR² (D ) 181 /2 MR²
_________________________

Answer 1

$\huge \blue{hello \: friends}$

___________________________________

$\bold \green{solution}$

_____________________

Using parallel axis theorem => Ip = Icm + Md²

=> [MR² /2 + 6 ( MR²/2 + M( 2R)² ]

=> [ MR² /2 + 54MR² /2 ]

=>[ 55MR² /2] + 7M ( 3R)²

=> 181MR² /2 Answer ✔

Hence ,

$\red{option \: d \: is \: answer}$

_________________________

$\boxed{hope \: it \: helps \: you}$

$\pink \star \pink{@Rajukumar111\star}$