Q 1 :    

Consider a rectangular sheet of solid materaial of length $l$ = 9 cm and with d = 4 cm. The coefficient of linear expansion is $\alpha =3.1\times {10}^{–5 }{\mathrm{K}}^{–1}$ at room temperature and one atmospheric pressure. The mass of sheet m = 0.1 kg and the specific heat capacity $C_v=900 \mathrm{J} {\mathrm{kg}}^{–1 }{\mathrm{K}}^{–1}$. If the amount of heat supplied to the material is $8.1\times {10}^{2 }\mathrm{J}$ then change in area of the rectangular sheet is:          [2025]

• $2.0\times {10}^{–6 }{\mathrm{m}}^2$

   

• $3.0\times {10}^{–7 }{\mathrm{m}}^2$

   

• $6.0\times {10}^{–7 }{\mathrm{m}}^2$

   

• $4.0\times {10}^{–7 }{\mathrm{m}}^2$