18) Two shafts ''A'' and ''B'' are made of same material. The shaft ''A'' is of diameter D and shaft ''B'' is of diameter D/2. The strength of shaft ''B'' is _____ as that of shaft ''A''.

19) A spur gear with pitch circle diameter D has number of teeth T. The module m is defined as

20) Lewis equations in spur gears is used to find the

21) The tapered roller bearings can take

22) An astronaut finishes some work "on the outside" of his satellite, which is in circular orbit around Earth. He leaves his wrench outside the satellite. The wrench will