Question

A conductor of length ‘l’ and area of crossection ‘A’ is stretched to ‘m’ times its original

length. What happens to its i) resistance ii) resistivity? Justify​

Answer 1

Answer:

resistance will decrese by m^2 times

resistivity won't change.

Explanation:

resistance given in pic

resistivity it is independent of length & area .

Answer 2

➢ QuesTioN is ,

• A conductor of length ‘l’ and area of crossection ‘A’ is stretched to ‘m’ times its original length.
• What happens to its
• i) resistance
• ii) resistivity? Justify.

☞ Answer is ☜

We will clear it from the question.

• a conductor of Length 'l' and are of crosssection 'A' is stretched to 'm' times of it's length
• it's new length is ( m x l ) from Original length ( l )

Now , we should have idea about resistance ,

i.e.

• Resistance is Directly proportional to the Length of conductor and inversely proportional to the Area of conductor.
• So it's new length will be ( m x l ) from Original length ( l ) the area of crosssection (after stretching ) will be = A / m

Formula→

R = Resistivity x Length / Area

So , Before stretching ,

• $Resistance = Resistivity \: \times \frac{l}{A}$

And after stretching ,

• it's resistance will be

• $Resistance = Resistivity \: \times \frac{ml}{A/m} \\ \\ Resistance = Resistivity \: \times \frac{ {m}^{2} l}{A}$

So , The Resistance will become m² times more than normal given condition , when it's length is Stretched to 'm' times .

So , The Resistance will become m² times more than normal given condition , when it's length is Stretched to 'm' times .And , Resistivity is independent of Length , so Resistivity will remain same