The resistance after stretching a wire becomes 16 times the initial resistance. Find the ratio of their area,ratio of the lens and ratio of the radii. KINDLY HELP ME WITH THIS QUESTION.
Answers
Explanation:
The electrical resistance of a wire would be expected to be greater for a longer wire, less for a wire of larger cross sectional area, and would be expected to depend upon the material out of which the wire is made.The resistance of a wire can be expressed as R=ρ
A
L
,
where,
ρ - Resistivity - the factor in the resistance which takes into account the nature of the material is the resistivity
L - Length of the conductor
A - Area of cross section of the conductor.
From this relation, we observe that the length is directly proportional to the resistance and the area of cross section is inversely proportional to the resistance.
That is, if L becomes 2 L, R becomes 2 R. R
′
=ρ
A
2L
. So, R = 2R'.
Hence, If the length of a wire is doubled, then its resistance becomes 2 times.
Answer:
Hello my friend
Explanation:
It's resistivity increases. When the wire is elongated its cross section area decrase. So hard to pass currunt through a narrow path and a long distance than before. Assuming constant total volume, if you double the length, the area has to reduce by a factor of two.
R′=ρA2L. So, R = 2R'. Hence, If the length of a wire is doubled, then its resistance becomes 2 times