Thermal Properties of Matter

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason (R).
Assertion A : Houses made of concrete roofs overlaid with foam keep the room hotter during summer.
Reason R : The layer of foam insulation prohibits heat transfer, as it contains air pockets.
In the light of the above statements, choose the correct answer from the options given below:

[Re-NEET 2024]

According to the law of equipartition of energy, the number of vibrational modes of a polyatomic gas at constant \(\gamma =\frac{{C}_{p}}{{C}_{v}}\) is (where \({C}_{p}\) and \({C}_{v}\) are th specific heat capacities of the gas at constant pressure and constant volume, respectively):

[Re-NEET 2024]

A metallic bar of Young's modulus \(0.5\times {10}^{11}N{m}^{-2}\), and the coefficient of linear thermal expansion \({10}^{-5}{{}^{∘}\mathrm{C}}^{-1}\), length 1 m and area of cross-section \({10}^{-3}{\mathrm{m}}^{2}\) is heated from \(0^\circ \mathrm{C}\) to \(100^\circ \mathrm{C}\) without expansion or bending. The compressive force developed in it is:

Water is used as a coolant in a nuclear reactor because of its:

Water is used as a coolant in a nuclear reactor because of its:

The quantities of heat required to raise the temperature of two solid copper sphere of radii \( r_{1} \) and \( r_{2}\left(r_{1}=1.5 r_{2}\right) \) through \( 1 \mathrm{~K} \) are in the ratio :

[NEET 2020]

Three stars \( A, B, C \) have surface temperatures \( T_{A}, T_{B}, T_{C} \) respectively. Star \(A\) appears bluish, star \(B\) appears reddish and star \(C\) yellowish. Hence,

[Re-NEET 2020]

The quantities of heat required to raise the temperature of two solid copper spheres of radii \( r_{1} \) and \( r_{2}\left(r_{1}=1.5 r_{2}\right) \) through \( 1 \mathrm{~K} \) are in the ratio

The value of coefficient of volume expansion of glycerin is \( 5 \times 10^{-4} \mathrm{~K}^{-1} \). The fractional change in the density of glycerin for a rise of \( 40^{\circ} \mathrm{C} \) in its temperature, is:-

Two thin metallic spherical shells of radii \( r_{1} \) and \( r_{2}\left(r_{1}

[JEE Main 2021, 31 Aug (Shift 2)]

The temperature of equal masses of three different liquids \(x, y\) and \(z\) are \(10^{\circ} C , 20^{\circ} C\) and \(30^{\circ} C\) respectively. The temperature of mixture when \(x\) is mixed with \(y\) is \(16^{\circ} C\) and that when \(y\) is mixed with \(z\) is \(26^{\circ} C\). The temperature of mixture when \(x\) and \(z\) are mixed will be:

[JEE Main 2021, 26 Aug (Shift 2)]