Two solid shafts 'A' and 'B' are made of the same material. The shaft 'A' is of 50 mm diameter and shaft 'B' is of 100 mm diameter. The strength of shaft 'B' is _________ as that of shaft A.

SIMPLE
AS WE KNOW THAT STRENGTH OF SHAFT IS MEASURED BY POLOR MODULUS
POLOR MODULUS = J/R
HERE SOLID SHAFT IS GIVEN SO FOR SOLID SHAFT POLOR MODULUS
=Pi/16 (D)^3
NOW AS Db =100
AND Da=50
So
Pi/16(Db)^3 DIVIDE BY Pi/16(Da)^3
AFTER CANCELATION WE GET
(Db/Da)^3
=(100/50)^3
=(2)^3
=8