Question

When any resistor is streched to double its original length then the new resistance is?

Answer 1

Since resistance is directly proportional to lenghth, then the resistance will also be halved

Answer 2

When any resistance is streched,

The results are as follows

(1) the length doubles

(2) the area of cross section reduces to half.

Let's understand this through an example,

Q.a wire of resistance 2 ohm is streched to double it's original length,such that the volume remains constant.what is the resistance of the streched wire?

Ans. Given resistance=R1=2 ohm

==>R1= rho l/A=2-------(1)

R2 as per the given information=

Rho 2l/A/2

=. rho l/A(2*2)------ from (1)

=. 2*2*2= 8

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Hope it helps!

Happy learning