Question

The sun rotates round itself in 27 days. what be the period of revolution,If sun were to expand twice its present size? Consider the sun to be sphere of uniform density.[M.I. of sphere = 2/5 MR²]

Answer 1

Let l₁, R₁ and T₁ be the M.I. radius and time period of the sun before expansion,

Let I₂,R₂ and T₂ be the M.I., radius and time period,respectively of the sun after expansion.

From the law of conservation of angular momentum,