A cord is wound round the circumference of wheel of radius r. The axis of the wheel is horizontal and the moment of inertia about it is I. A weight mg is attached to the cord at the end. The weight falls from rest. After falling through a distance 'h', the square of angular velocity of wheel will be:
1
2gh
2
\(\frac{{2gh}}{{I + m{r^2}}}\)
3
\(\frac{{2mgh}}{{I + m{r^2}}}\)
4
\(\frac{{2mgh}}{{I + 2m{r^2}}}\)