Consider a rectangular sheet of solid material of length =9 ~cm and width d=4 ~cm . The coefficient of linear expansion is α=3.1 × 10^ -5 ~K^ -1 at room temperature and one atmospheric pressure. The mass of sheet m=0.1

Correct answer: A. 2.0 × 10^ -6 ~m^2 aligned & Δ Q=ms Δ T & 8.1 × 10^2=0.1 × 900 × Δ T & Δ A=A_0 2 α Δ ~T=2.0 × 10^ -6 ~m^2 aligned

JEE Main 20254 AprilEvening Shift

JEE Main 2025 · 4 April · Evening Shift · Physics · Thermal Properties of Matter

Consider a rectangular sheet of solid material of length =9 ~cm and...

Consider a rectangular sheet of solid material of length

\ell=9 \mathrm{~cm}

and width

\mathrm{d}=4 \mathrm{~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

\mathrm{m}=0.1 \mathrm{~kg}

and the specific heat capacity

\mathrm{C}_{\mathrm{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 :-

A. $2.0 \times 10^{-6} \mathrm{~m}^2$

\begin{aligned} & \Delta \mathrm{Q}=\mathrm{ms} \Delta \mathrm{T} \\ & 8.1 \times 10^2=0.1 \times 900 \times \Delta \mathrm{T} \\ & \Delta \mathrm{A}=\mathrm{A}_0 2 \alpha \Delta \mathrm{~T}=2.0 \times 10^{-6} \mathrm{~m}^2\end{aligned}