Question

A resistance wire of 4 Ohm resistance is doubled itself calculate the new resistance of the wire

Answer 1

Answer:

We consider wire is doubled on it means to fold the length of wirr.It means its length will get half and area of cross section will get doubled

Let the resistance of the wire orginally'R' of length'L' and area of cross-section 'A'with resistivity of material is'p'

Then

R=pl/A=4ohm

Now, for new arragement, p'=p

1'=1/2A'=2A

Thus,

R'=p'l'/A'=p(1/2)÷2A=1/4(pl/A)=1/4R=1/4×4=1ohm