Q50.-A uniform disc of radius r is to be suspended through a small hole made in the disc. Find the min possible time period of the disc for small oscillation .Wat should be the distance of the hole from the centre for min time period? 

                                                    ......................2(r/g)^{1/2   ,}  r/

                                       Exp !!!!!!!!!!!!!!!

pleeeeeeeeeeeeeeeeez    reply yaar!!!!!!!!!!!!!!!!!!!!!

Here you go:

Consider a disc of radius r and take any small point(hole) at a distance x from it.Now letr the disc be rotated thru a small angle

Now Torque(T)=xmgsin

But T=I(I is the MI about the hole)

I=(mr^2/2)+mx^2

so we get w=

Differentiate to find x=r/sqrt2

And You Have The Answer!!!!