Question

A wire is cut into 3equal parts.These parts are twisted together. Calculate the resistance of the original wire if the resistance of the twisted wire is 6ohm?

Answer 1

Answer:

well keep it simple

lets suppose a resistance of R ohms.

since, R= (P*L)/A(p=resistivity of the material)(L= length of the material)(A=cross-sectional area os the materil.)

thus, when we cut resistance into three equal pieces(lets suppose):

new r=(p*(L/3))/A which makes it as r= ((p*L)/A)1/3.

thus new r=R/3, now if you connect three resistances of value R/3 each in parallel, you get:

r=R+R+R/3*3*3

implies, r=3R/27 i.e. r=R/9 which will be the required and hence the right