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 m2 and 4.5 10-5 m2, 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
- 2
- 1
- 4
- 5
Answer
(4) 5
Solution
Y = FLA L; the load F and the extension L are the same for both wires.
Y LA
YAYB = LALB ABAA = 6.05.4 4.5 10-53.0 10-5
= 109 32 = 53
x = 5
Answer: (4)