Question

a wire of resistance 2 ohm is stretched to double its length.what is the new resistance of the wire?what is the change in resistivity of the wire?

Answer 1

Answer:

The resistance of a uniform wire is directly proportional to its length and inversely proportional to its cross-sectional area. Here, R is theresistance of the wire in ohms, l is thelength of the wire in meters, and A is the cross-sectional area of the wire in .

R=p. l/A........(1)

the volume of the conductor is (v)= A/2 into 2L(as volume is constant)

R'=p. 2L/A/2

=p. 4L/A

=4 L/A

=4R

if the resistance is two ohm then the value of R is 2

R'=4R

#R'=4 into 2

#R'=8

°•°R'=8 ohm

Answer 2

Answer:

we know

R=p. l/A........(1)

the volume of the conductor is (v)= A/2 into 2L(as volume is constant)

R'=p. 2L/A/2

=p. 4L/A

=4 L/A

=4R

if the resistance is two ohm then the value of R is 2

R'=4R

#R'=4 into 2

#R'=8

°•°R'=8 ohm

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