Question

65. A copper wire has a resistance of 10 ohm. It is
stretched by one-tenth of its original length.
Then its resistance will be
(i) 10ohm
(ii) 12.1 ohm
(iii) 9ohm
(iv) 11 ohm​

Answer 1

Answer:

https://goo.gl/search/.+A+copper+wire+has+a+resistance+of+10+ohm.+It+is%0Astretched+by+one-tenth+of+its+original+length.%0AThen+its+resistance+will+be%0A(i)+10ohm%0A(ii)+12.1+ohm%0A(iii)+9ohm%0A(iv)+11+ohm%E2%80%8B

A wire has a resistance of 10 ohms. It is stretched by 10% of its ... It has a resistance of 10 ohms so 1 ohm per metre. When stretched it would become (approximately) 10% thinner, in cross sectional area, so now the resistivity is 1.1 ohms per metre. It is now 11 m long, so the resistance should be 12.1 ohm.