Question

Explain how the resistance of the conductor varies if
A)length is doubled
B) area is doubled
C) area is halved

Answer 1

. L=Length A=Area R=Resistivity ρ=constant According to the problem:- R= ρL/A Now if the length is doubled then area will be halved (bcoz the material of wire provided is fixed) A & B.......so if length is doubled and area is halved. new length=2L new area =A/2

so R =ρ4L/A (put the values)

so resistivity becomes 4 times the original

D.....Now if length is halved (area is doubled) new length=L/2 new area= 2A so

R=ρL / 4A

So resistivity becomes 1/4 th times

C......Length and area doubled new area=2A new length=2L

R =ρL/A

so Resistivity remains the same