JEE Main20207 Jan 2020Morning ShiftPhysicsMechanical Properties of SolidsActual
Speed of a transverse wave on a straight wire (mass 6.0 g , length 60 c m and area of cross-section 1.0 m m 2 is 90 m s - 1 . If the Young's modulus of wire is 16 × 10 11 N m - 2 , the extension of wire over its natural length is:
Options
- A0.03   m m
- B0.02   m m
- C0.04   m m
- D0.01   m m
Correct answer
A. 0.03   m m
Step-by-step solution
v = T μ ⇒ T = μ v 2 ⇒ μ v 2 A = Y ∆ l l ⇒ ∆ l = μ v 2 l A Y After substituting value of μ , v , l , A and Y we get ∆ l = 0 . 3 m m