Question

Calculate the resistance offered by a wire if its resistivity is 12 ohm. m, with a length of
6m and a cross sectional area of 0.25 m square​

Answer 1

Answer:

Given that,

Cross section area of wire , A=5.0×10

−6

m

2

Resistivity of wire , ρ=50×10

−8

Ωm

Let l be the length of wire

Potential difference across wire , V=6.0 V

Current through the wire , I=3.0 A

∴ Resistance of wire , R=

I

V

=

3

6

=2 Ω

Also , R=ρ

A

l

⟹2=50×10

−8

×

5.0×10

−6

l

⟹l=

50×10

−8

2×5.0×10

−6

=20 m

⟹Length of wire, l=20 m

Answer 2

Answer:

Explanation:

Given , resistivity is 12 ohm m

Length of wire is 6m

Area is 0.25 m^2

Resistance = resistivity × length ÷ Area

=12 × 6 ÷ 0.25

=288 ohm