Moment of inertia of a rod of mass ' M ' and length 'L' about an axis passing through its center and normal to its length is ' α '. Now the rod is cut into two equal part

Question

Moment of inertia of a rod of mass ' M ' and length 'L' about an axis passing through its center and normal to its length is ' $α$ '. Now the rod is cut into two equal parts and these parts are joined symmetrically to form a cross shape. Moment of inertia of cross about an axis passing through its center and normal to plane containing cross is :

Question diagram: Moment of inertia of a rod of mass ' M ' and lengt

Options:

Answer:

B

Solution:

$α = \frac{M ℓ ^{2}}{12}$
$α^{'} = 2 [\frac{\frac{M}{2} ( \frac{ℓ}{2} ) ^{2}}{12}] α^{'} = \frac{M ℓ ^{2}}{48} = \frac{α}{4}$
Correct option is (2)

TestHub · Accepted Answer

α = 12 M ℓ 2 ​ ​ α ′ = 2 [ 12 2 M ​ ( 2 ℓ ​ ) 2 ​ ] α ′ = 48 M ℓ 2 ​ = 4 α ​ ​ Correct option is (2)

Physics - Rotation Question with Solution | TestHub

Options:

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