Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A conducting wire has length L1 and diameter d1 . After stretching the same wire length becomes L2 and diameter d2 . The ratio of resistance before and after strectching is
PhysicsCurrent ElectricityMHT CETMHT CET 2018
Options:
  • A d24:d14
  • B d14:d24
  • C d22:d12
  • D d12:d22
Solution:
2407 Upvotes Verified Answer
The correct answer is: d24:d14
R 1 R 2 = L 1 L 2 × A 2 A 1 = L 1 L 2 × π d 22 4 π d 1 2 4 ...(1)
L 1 d 1 2 = L 2 d 2 2 ...(2)
L 1 L 2 = d 2 d 1 2
R 1 R 2 = L 1 L 2 × d 2 d 1 2
= d 2 4 d 1 4

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.