Question

a wire of resistance 3 ohm and 10 cm is stretched to length 30cm assuming that is has acuniform cross section what will be the new resistance

Answer 1

Hi!!!

here is ur answer!!

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as wire of 10 cm length is stretched to 30cm i.e 3 times...

therefore,

resistance becomes 9 times its resistance i. e 3* 9 = 27 ohm

R1 = raw 30/ (a /3 )= 9[ raw 10/a]

R2 = raw 10/ a. (put in above eq.)

R1 = 9R
=> 9*3 = 27ohm...

therefore R = 27 ohm...

hope this helps u!!

Answer 2

Given :- The initial resistance of wire R¹ is 3ohm

When length of the wire is 10cm

It is stretched to length 30cm that means it's length is increased 3 times the initial one.

Resistance is directly proportional to Length of the wire

If we increase the length of the wire the resistance will also increase.

Length is increased 3 times

Resistance will be also increased 3 times

R² = 9ohm