A wire of length L and area of cross section A was drawn into a wire of double its length by melting it .if its original resistivity and resistance were p and R respectively what will be its new resistivity and resistance
Answers
The new resistance of the wire is 4R and resistivity remains unchanged.
Explanation:
As we can see that
The volume is constant so
L.A = L'.A'
We know that
R = ρ x L / A
When a wire is double its length wold become double and are of cross section would be halved. i.e.
- Length of wire = 2l
- Area of cross section = A /2
Then we have
R1 = 2 ρ L1 / A /2 = 4 ρ L/ A
Where R1 is the new resistance.
Therefore the new resistance of the wire is 4R and resistivity remains unchanged.
Also learn more
Calculate area of cross section of wire if its length is 1m resistance is 23 ohm and resistivity of the material is 1.84*10-6 ohm ?
https://brainly.in/question/3329598
Answer:
Explanation:
Solution :-
We know that, R = ρ l/A
When the wire is doubled by melting, its length would become double and area of cross-section become halved
Length of wire = 2l
Area of cross-section = A/2
Thus we have, R₁ 2ρl/A/2 = 4ρl/A
where R₁ is the new resistance.
Therefore, the new resistance of wire is 4 R.
As resistivity of the material is the characteristic of a given material
Hence, it remains unchanged.