# If uncertainty in position and momentum are equal, then uncertainty in velocity is :

$\begin {array} {1 1} (1)\;\sqrt{\large\frac{h}{\pi}} & \quad (2)\;\large\frac{1}{2m}\sqrt{\large\frac{h}{\pi}} \\ (3)\;\sqrt{\large\frac{h}{2\pi}} & \quad (4)\;\large\frac{1}{m}\sqrt{\large\frac{h}{\pi}} \end {array}$