A car is travelling along a curved road of radius r. If the coefficient of friction between the tyres and the road is $/mu$ , the car will skid if its speed exceeds :

Question

$\begin {array} {1 1} (1)\;2\sqrt{\mu rg} & \quad (2)\;\sqrt{3\mu rg} \\ (3)\;\sqrt{2\mu rg} & \quad (4)\;\sqrt{\mu rg} \end {array}$