QJEEM19Ph2e1c: JEE Main 2019 Physics - Class 11 JEEM19Ph2e1c Solution: At 40 o C, a brass wire of 1 mm radius is hung from the…

At 40^o 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^oC to 20^oC 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 /^oC and 10¹¹ N/m ² , respectively; g= 10 ms^–2 )