A 3 m long wire of radius 3 mm shows an extension of 0.1 mm when loaded vertically by a mass of 50 kg in an experiment to determine Young's modulus. The value of Young's modulus of the wire as per this experiment is P 1011 N m-2, where the value of P is: (Take g = 3 m/s2)
- 2.5
- 25
- 10
- 5
Answer
(4) 5
Solution
Y = F/A L/L = mgL r2 L
Here m = 50 kg, g = 3 m/s2, L = 3 m, r = 3 10-3 m, L = 1 10-4 m
Y = 50 3 3 9 10-6 10-4
= 4509 1010
= 5 1011 N m-2
P = 5
Answer: (4)