*8. +7. Determine the resistance of a copper wire having a length of 1 km and diameter of 0.5 mm. (Given: p = Resistivity of copper = 1.7 x 108Ω m) [2 Marks] =
Answers
Answered by
0
ans:
85
Correct option is
A
85
ρ= Resisivity of copper =1.7×10
−3
Ωm
convertung all measures into metres.
L=1km=1000m=10
3
m
d=0.5mm=0.5×10
−3
m
If r is the radius of the wire then, its area of cross-section
A=πr
2
∴A=π×(
2
d
)
2
=
4
π
(0.5×10
−3
)
2
m
2
R=ρ
A
L
=
0.2×10
−3
m
2
1.7×10
−3
Ωm×(10
3
m)
=85Ω plz mark as brainliest ans
Answered by
0
Explanation:
ρ= Resisivity of copper =1.7×10 −3Ωm
convertung all measures into metres.
L=1km=1000m=103m
d=0.5mm=0.5×10−3m
If r is the radius of the wire then, its area of cross-section
A=πr 2
∴A=π×( d/2) =π\4(0.5×10 −3 )2 m2
R=ρ L/A = 1.7×10-3 Ωm×(10 3 m)=85Ω
Similar questions