If a disc of mass m and radius r is reshaped into a ring of radius2r, the mass remining the same, the radius of gyration about centrodal axis perpendicular to plane goes up by a factor of

If a disc of mass m and radius r is reshaped into a ring of radius2r,

1.	If a disc of mass m and radius r is reshaped into a ring of radius2r, the mass remining the same, the radius of gyration about centrodal axis perpendicular to plane goes up by a factor of
Answer» <html><body><p>`<a href="https://interviewquestions.tuteehub.com/tag/sqrt-1223129" style="font-weight:bold;" target="_blank" title="Click to know more about SQRT">SQRT</a>(2)`<br/>2<br/>`2 sqrt(2)`<br/>4</p>Solution :The radius of <a href="https://interviewquestions.tuteehub.com/tag/gyration-1014165" style="font-weight:bold;" target="_blank" title="Click to know more about GYRATION">GYRATION</a>, `K_(D)=sqrt((I_(D))/(m))=sqrt(((1)/(2)mr^(2))/(m))=(<a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a>)/(sqrt(2))` <br/> `K_(R)=sqrt((I_(PR))/(m))=sqrt((m(<a href="https://interviewquestions.tuteehub.com/tag/2r-300472" style="font-weight:bold;" target="_blank" title="Click to know more about 2R">2R</a>)^(2))/(m))=2r` <br/> `:. (K_(R))/(K_(D))=2 sqrt(2)`.</body></html>