Physics - NLM Question with Solution | TestHub

In the wedge frame, pseudo force $ma$ acts rightward and gravity $mg$ downward.

At rest relative to the wedge: $ma\cos \theta =mg\sin \theta$

$\tan \theta =\frac{a}{g}=\frac{5}{10}=\frac{1}{2}$

Increasing a gives a net force up the incline; decreasing a gives a net force down the incline.

Therefore A, B and C are correct.