IIT JEE , AIEEE Forum - Physics , Mechanics

v_gurucharan

what is poisson's ratio? where is it used/hw is it used?what's its application?

give an example.............

lonewolf07

poisson,s ratio is the ratio of laterai strain to longitudinal strain on a tin cylindrical body = sigma = (d/D) / (l/L)
Used in elastisity
used to determine any unknown frm above formula

lonewolf07

4 more.........see HCV

chimanshu_007

hiiee

Poission's ratio - Wen a wire susepended frm 1 end and loaded at the other , it not only increases its length but also decreases its diameter . In other words , an elongtational starin is accompanied by a lateral starin also in a direction perpedcular to its length. The ratio of lateral strain to the longitudanal strain is called poission's ratio ()

Let L and D be the original length and diameter of the wire resp. . Suppose delta L and delta D be the small increase in length and correspondingly small decrease in diameter of the wire

longitudinal strain = del. L / L

and lateral strain = - (del. D / D)

so

= (-del D/D) / (del. L / L)

P.S- its a pure no. and hence dimension less .

its value lies between -1 and 0.5

but it is never -ive in actual practise and its practical value lies b/w 0 and 0.5

v_gurucharan

what to answer if asked abt. no. :
P.S- its a pure no. and hence dimension less .
its value lies between -1 and 0.5

but it is never -ive in actual practise and its practical value lies b/w 0 and 0.5

u have given 2 answers??????????????
but well done!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

chimanshu_007

well buddy...theoratically its value lies btw -1 to 0.5

i mean its value is -1 to 0.5 wen caculated with the fromulas....

but practically , it never comes out to be -ive....it is always btw 0 and 0.5

i think u can understand diff. btw theoratical and practical...

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