At 40°C, a brass wire of 1 mm radius is hung from the ceiling. A small mass, M is hung from the free end of the wire. When the wire is cooled down from 40°C to 20°C it regains its original length of 0.2 m. The value of M is close to:(Coefficient of linear expansion and Young's modulus of brass are 10-5/℃ and 1011 N/m2, respectively; g = 10 ms-2)

At 40°C, a brass wire of 1 mm radius is hung from the ceiling. A smal

1.	At 40°C, a brass wire of 1 mm radius is hung from the ceiling. A small mass, M is hung from the free end of the wire. When the wire is cooled down from 40°C to 20°C it regains its original length of 0.2 m. The value of M is close to:(Coefficient of linear expansion and Young's modulus of brass are 10-5/℃ and 1011 N/m2, respectively; g = 10 ms-2)
A.	9 kg
B.	0.5 kg
C.	1.5 kg
D.	0.9 kg
Answer» B. 0.5 kg