The addendum is less than dedendum

The pitch circle diameter is equal to the product of module and number of teeth

The pitch circle is always greater than the base circle

all of the above

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