Which has the higher shear stress for a given elastic torque

Which has the higher shear stress for a given elastic torque? a. a one-inch diameter rod, or b. a two-inch diameter rod.

Solution

One inch rod will have higher shear stress as we know that shear stress is inversely proportional to the cube of diameter hence the one inch diameter rod will have more shear stress as compared to two inch diameter rod for the same elastic torque acting on both the rods.