Question

The Sun rotates around its centre once in 27 days. What will be the period of revolution if the Sun were to expand to twice its present radius without any external influence? Assume the Sun to be a sphere of uniform density.

विकल्प

• 100 days

• 105 days

• 115 days

• 108 days

Answer 1

108 days

Explanation:

In the absence of external torque, angular momentum is conserved.

I₁ω₁ = I₂ω₂

`(2/5 MR_1^2)((2pi)/(T_1)) = (2/5 MR_2^2)((2pi)/T_2)`

`T_2 = T_1((R_2)/(R_1))^2`

= `27 xx ((2R_1)/(R_1))^2`

= 27 × 4

= 108 days