A block is placed on a rough inclined plane of inclination `theta = 30^(@)`. If the force to drag it along the plane is to be smaller than to lift it. The coefficient of friction `mu` should be less than

Explanation

`mg(sin theta+mu cos theta)lt mg`
`sin 30^(@)+mu cos 30^(@)lt 1`
`(1)/(2)+ mu (sqrt(3))/(2)lt 1`
`rArr mu (sqrt(3))/(2)lt 1//2 rArr mu lt (1)/(sqrt(3))`