Torque Formula:
T = d * F * sin angle
a) if the force is doubled, torque is doubled ( directly proportional)
For example, if force is 2 N, and distance is 2 m ,
T= 2*2* sin 90 = 4 Nm
If force is doubled:
T= 2*4 * sin90 = 8 Nm
b) If the distance of the center of rotation is doubled , Torque is also doubled ( same as "a")
c) If angle decreases 45° (90 - 45 = 45 )
T= 2*2*sin45 = 2.82 Nm
Torque also decreases