Question

A wire of length l and area of cross - section A was drawn into a wire of double its length by
meiting it. If its original resistivity and resistance were p and R respectiel, hat will be its new
resistivity and resistance ?​

Answer 1

Answer:

We know, R =ρ l/A When a wire is doubled by melting its length would become double and area of the cross-section would be halved i.e., length of wire = 2l and area of cross- section = A/2. where R, is the new resistance. Therefore, the new resistance of the wire is 4 R. As resistivity of a material is the characteristic of a given material, hence it remains unchanged.