99 Percentile Qs Bank for JEE MainPhysicsMechanical Properties of Solids
One end of thick horizontal copper wire of length '2L' and radius '2R' is welded to an end of another thin horizontal copper wire of length 'L' and radius 'R'. When they are stretched by applying same force at two ends, the ratio of the elongation in the thick wire to that in thin wire is
Options
- A1: 2
- B4: 1
- C2: 1
- D1: 1
Correct answer
C. 2: 1
Step-by-step solution
Correct option is ( C ) We have change in length l = F . l YA Since the two rods are in series array l ( F ₁ )_ rest = ( F ₂ )_ ret l 1 R ² ( A = R ² ) l ₁ l ₂ = l ₁ l ₂ R ₂ ² R ₁ ² l ₁ l ₂ = 2 ~L ~L R ₁ ² 4 R ₁ ² l ₁ l ₂ = 1 2 l ₂ l ₁ = 2 1 =2 array