For same field torque will be higher in loop with higher magnetic moment. And for same current magnetic moment is higher in loop with highest area.
For same perimeter, the area is highest for circle, so circle will experience more torque then any other figure (Be it triangle, squrare, rectangle, hexagon or any random figure.
Krishna Gopal Singh
B.Tech Chemical Engg
IIT Delhi 2002
Currently doing PhD from IIT Delhi