JEE Main202120 Jul 2021Evening ShiftPhysicsMechanical Properties of SolidsActual
The length of a metal wire is ℓ 1 , when the tension in it is T 1 and is ℓ 2 when the tension is T 2 . The natural length of the wire is:
Options
- Aℓ 1 ℓ 2
- Bℓ 1   T 2 - ℓ 2   T 1   T 2 - T 1
- Cℓ 1   T 2 + ℓ 2   T 1   T 2 + T 1
- Dℓ 1 + ℓ 2 2
Correct answer
B. ℓ 1   T 2 - ℓ 2   T 1   T 2 - T 1
Step-by-step solution
T 1 = k ℓ 1 - ℓ 0 T 2 = k ℓ 2 - ℓ 0 T 1   T 2 = ℓ 1 - ℓ 0 ℓ 2 - ℓ 0 T 1 ℓ 2 - T 1 ℓ 0 =   T 2 ℓ 1 - T 2 ℓ 0 T 2 ℓ 1 - T 1 ℓ 2   T 2 - T 2 = ℓ 0