less than 20 d

greater than 30 d

between 20 d and 30 d

equal to inside diameter of pipe

variations in load acting on a member

variations in properties of materials in a member

abrupt change of cross-section

all of these

elastic limit

Young's modulus

ultimate tensile strength

endurance limit

enhance the load carrying capacity of the jack

reduce the effort needed for lifting the working load

prevent the rotation of load being lifted

reduce the value of frictional torque

shaft B is better than shaft A

shaft A is better than shaft B

both the shafts are equally good

none of these