A wire is stretched so that its length becomes 6/5 times its original length. If its original resistance is 25ohm, find its new resistance and resistivity
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Answered by
6
R is directly proportional to L
.: 25 × 6 ÷ 5 is the new resistance
= 150 ÷ 5
=30ohm is the new resistance
I DONT KNOW HOW TO FIND RESISTIVITY ....
Answered by
5
R = p L/A
R = 25 ohm
Volume of material in the conductor = LA
Vol of the conductor remains the same
Vol = AL
= A'L'
A' = AL/L'
After streching the wire
L' = 6L/5
A' = 5AL/6L
= 5A/6
Resistance of streched wire = R'
= pL'/A'
= p(6L/5) × {6 / (5A) }
R' = 36pL / 25A
R' = 36R / 25
Now Resistance ,
= 36×25 / 25ohm
= 36 Ohm
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