A triangular block of mass m rests on a fixed rough inclined plane having friction coefficient $\mu$ with the block. A horizontal force F is applied to it as shown in figure, then the correct statement is :

$N=mg\cos \theta +F\sin \theta$

Also, if $mg\sin \theta +F\cos \theta$, then the friction force acting on the block is zero.

$f_{static}{]}_{\max imum}=\mu N=\mu (mg\cos \theta +F\sin \theta )$

(The maximum static friction that can act on a body under a given solution is known as limiting friction under the given conditions.)