A wire of length 15cm gives 10Ω resistance in a circuit. Find the resistance of the wire if (a) the wire is stretched to Double its length (b) the wire is doubled on itself.
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5
If the wire is stretched to double its length then its length increases by 2 times and its area decreases by 2 times
R resistance is d proportional to l/A
Hence resistance increases by 4 times.
Hence R = 40 ohm.
If the wire is double on itself then resistance becomes 10/4 = 2.5 ohm
R resistance is d proportional to l/A
Hence resistance increases by 4 times.
Hence R = 40 ohm.
If the wire is double on itself then resistance becomes 10/4 = 2.5 ohm
Rishav1604:
thnx
Wlcm
Answered by
3
Answer:
R=el/a
Where R=resistance,e=resistivity,l=length of conductor ,a=cross section area of conductor
If length is doubled that means area is halved (if you stretch a sponge rubber,you observe that it's area changes,,,like wise)
Then ‘e’ resistivity is const ,it doesn't depend on length or area.it depends on type of material to be used as conductor
So R2 /R1 =4
Then R2=40
IF the wire double,(not length ) just it's resistance also doubled (R=2R)
as resistance is proportional to length
So R2=20
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