Question

A wire of a uniform cross section area is cut to three equal segments. The resistivity ‘rho’ of each segment will be *

Answer 1

Answer:

Same as before

Explanation:

Resistivity is a property of material.

because the material is same, the resistivity will be same.

Thank you.

Answer 2

Answer:

Resistance of wire =R, length of wire =l On cutting the wire into n equal parts, resistance of each part of wire becomes Ri=Rn, and length becomes (l=ln). When each part remains unchanged. V=Final volume=Initial volume

Therefore, V=AFlF=Aili

Now, the initial length will be li=ln and final length =lP=l

APl=Ailn

AFAi=1n

∴RFRi=ρlFAiAFρli=lFli×AiAf

RF=n2Ri(∴Ri=Rn)

∴RF=n2Rn=nR

Hence, resistance of each stretched part= nR

On connecting these parts in parallel, the resultant resistance will be

1RP=1nR+1nR+1nR+...n times

1RP=nnR

⇒RP=R