The diameter of a flywheel is increased by 1% . Increase in its moment of interia about the central axis is

Options

A. `1%`
B. `0.5%`
C. `2%`
D. `4%`

Answer

C

Explanation

Differentiating
`because" "l=MR^(2)" …(i)"`
`therefore" "dl=M.2RdR" …(ii)"`
On dividing Eq. (ii) by Eq. (i), we get
`(dl)/(l)=2dR//R`
`(dl)/(l)=0+2(dR)/(R)`
`therefore" "(dl)/(l)xx100=2((dR)/(R))xx100`
`=2xx(1)/(100)xx100=2%`