Their radii (radiuses) can.
Their radii, diameters or circumferences - in all three cases the ratio between the axle and wheel are the same.
The mechanical advantage of the wheel and axle does not exist
Either the circumferences, the diameters or the radii: the ratios will be the same in all three cases.
The mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle.
In theory a wheel and axle has only one mechanical advantage. You can find the ideal mechanical advantage of a wheel and axle by dividing the radius of the wheel by the radius of the axle.
we can find out mechanical advantage of wheel and axle by using forumla i,e, mechanical advantage=load/effort
Actual Mechanical Advantage is the ratio of Force outputed to Force inputed. (AMA=Fo/Fi) Similarly, IMA (Ideal Mechanical Advantage) = di/do