Q.

A metallic bar of Young's modulus, 0.5×1011 N m-2 and coefficient of linear thermal expansion 10-5°C-1, length 1 m and area of cross-section 10-3m2 is heated from 0°C to 100°C without expansion or bending. The compressive force developed in it is:           [2024]
 

1 5×103N  
2 50×103N  
3 100×103N  
4 2×103N  

Ans.

(2)

Y=0.5×1011N/m2,  α=10-5/°C

l=1m,  A=10-3m2,  ΔT=100°C

F=YAαΔT

F=0.5×1011×10-3×10-5×100

F=50×103N