JEE Main202628 January 2026Morning ShiftPhysicsMechanical Properties of SolidsActual
Two wires A and B made of different materials of lengths 6.0 cm and 5.4 cm, respectively and area of cross sections 3.0 10⁻⁵ ~m ² and 4.5 10⁻⁵ ~m ² , respectively are stretched by the same magnitude under a given load. The ratio of the Young's modulus of A to that of B is x: 3 . The value of x is _ _ _ _ .
Options
- A2
- B1
- C4
- D5
Correct answer
D. 5
Step-by-step solution
Young's modulus: Y = = F/A L/L . When the same force is applied and both wires stretch by the same extension L , the ratio of Young's moduli is: Y_A Y_B = F/A_A L/L_A L/L_B F/A_B = A_B A_A L_A L_B = 4.5 10⁻⁵ 3.0 10⁻⁵ 6.0 5.4 = 1.5 10 9 = 5 3 . Therefore x : 3 = 5 : 3 , giving x = 5 .