a wire of resistance 2 ohm is streched to double its length such that its volume remains constant find the new resistance
Answers
Answered by
0
mark as brianlist......m
Answered by
1
Answer:
The answer will be 8 ohm
Explanation:
According to the question:
Length is doubled, without changing the volume, thus the area of the cross-section will be reduced by a factor of 2 as the length is inversely proportional to the area.
Previous Resistance is R1 = 2 ohm = P l/A
=> The new length is 2l
=> The new area of cross-section is A/2
=> R2 = P 2l / (A/2)
=> R2 = P 2l X 2 / A
=> R2 = P 4l / A
=> R2 = 4 X P l/A
As P l/A is R1
=> R2 = 4 (R1)
As R1 = 2ohm
=> R2 = 4 X 2 = 8ohm
Similar questions