Question

The value of youngs modulus for a material is 24*10^11dyn.cm^2.
what will be the range of value of its modulus od rigidity?...
please hlp me to do this one .....

Answer 1

E = 2G (1+m)

E = Young's modulus or modulus of elasticity
G = modulus of rigidity
m = Poisson's ratio

given E = 24* 10^11 dyne/cm^2

most materials have a range of 0 to 0.5 value of "m"

based on that,
at m =0
G = E/2 = 12* 10^11

at m= 0.5

E = 2G(1+0.5)
G = E/3 = 8* 10^11

m =0 , means perfectly rigid --» means no deformation
sometimes,
m=1, for linear elastic bodies

but in practical cases m value ranges from 0.2 to 0.5
at m = 0.2
G =E/2.4 = 10* 10^11


so G varies from 10*10^11 to 8*10^11 in practical application
hope you understand
any doubts, comment ;))