A wire of uniform cross -section and length l has a resistance of 4ohm . The wire is cut into 4 equal pieces. Each piece is then stretched to length 'l'.Thereafter the 4 wires are joined in parallel. Calculate the net resistance.
Asked by mkvinvestments6 | 20th Jul, 2015, 09:30: PM
Expert Answer:
Resistance of a material depends upon the nature of material, length of the wire and the area of cross section.
Let the resistivity of the material be 
,length of the wire be l and the area of cross section be A.
Now the wire is cut into four equal pieces and stretched to the initial length l.
When we stretch it the new length of the wire will be the same of each piece but the area will get reduced to one-fourth.
l'=l
Now connect the four pieces in parallel, the equivalent resistance will be,
Thus, the net resistance will be the same.
,length of the wire be l and the area of cross section be A.Answered by Faiza Lambe | 21st Jul, 2015, 08:04: AM
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