Question

Two similar wires of same length and same area of cross-section but of different material,, having resistivity p, and p2 are connected end to end (in series). Calculate the effective resistivity of their combination.

Answer 1

Answer:

R

1

=

A

ρ

1

l

R

2

=

A

ρ

2

l

R+R=

A

2ρl

∴2R=R

1

+R

2

2ρ=ρ

1

+ρ

2

∴ρ=

2

1

(ρ

1

+ρ

2

)