Question
Sat May 12, 2012 By: Neerja Pathak
 

How does resistance of wire changes when : 1)It's length tripled? 2)It's diameter is tripled ? 3) It's material is changed to one whose resistivity is three times ? 2)

Expert Reply
Sat May 12, 2012
The resistance of a wire is directly proportional to its length and inversely proportional to its area (or square of inverse of diameter).
Therefore
1) When the length is tripled then its resistance will also becomes three times.
2) If the diameter get tripled then its resistance becomes one ninth of the initial reistance.
3) If the material is changed to one whose resistivity is three times then again its resistance will be three times.
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