Physics - Heat & Thermo Question with Solution | TestHub

At$40°\mathrm{C},$a brass wire of$1\mathrm{ }\mathrm{m}\mathrm{m}$radius is hung from the ceiling. A small mass,$\mathrm{M}$is hung from the free end of the wire. When the wire is cooled down from$40°\mathrm{C}\mathrm{ }$to$20°\mathrm{C}$it regains its original length of$0.2 \mathrm{m}.$The value of$\mathrm{M}$is close to:
(Coefficient of linear expansion and Young’s modulus of brass are${10}^{-5}{/}^{°}\mathrm{C}$and${10}^{11}\mathrm{ }\mathrm{N}/{\mathrm{m}}^2,$respectively;$\mathrm{g}=10 \mathrm{m}\mathrm{ }{\mathrm{s}}^{-2}$)