A bar of cross-sectional area 2 cm2 and length 100 cm fixed to rigid supports at both ends at a temperature of 25°C. The bar is subjected to an increases in temperature of 30°C. If the coefficient of linear thermal expansion of the material is 10 × 10-6/°C and Young’s modulus 2 × 105 N/mm2 the stress in the bar is

A bar of cross-sectional area 2 cm2 and length 100 cm fixed to rigid s

1.	A bar of cross-sectional area 2 cm2 and length 100 cm fixed to rigid supports at both ends at a temperature of 25°C. The bar is subjected to an increases in temperature of 30°C. If the coefficient of linear thermal expansion of the material is 10 × 10-6/°C and Young’s modulus 2 × 105 N/mm2 the stress in the bar is
A.	10 N/mm2 comp
B.	20 N/mm2 comp
C.	50 N/mm2 comp
D.	50 N/mm2 tension
Answer» B. 20 N/mm2 comp