a$.$ A force F acts on a rigid object.

i$.$ Under what conditions will the force produce a force $-$ couple system acting on the object.

Illustrate with diagrams. $[3]$

ii$.$ What will be the effect of the couple on the rigid object? $[2]$

b$.$ Replace the following non$-$concurrent forces with a force$-$couple system at the origin O$.[15][$Look at the axes well$]$

c$.$ What will be the point of application of the forcecouple? $[5]$