Thermal Properties of MatterNEET Physics · Class 11 · NCERT Chapter 10

You can expect 1 to 2 questions from this chapter in NEET 2027. The chapter has medium PYQ frequency. Calorimetry, latent heat, conduction (especially composite slabs), Stefan-Boltzmann's law and Newton's law of cooling are the favourite topics.

T_K equals T_C plus 273.15. T_F equals (9 over 5) times T_C plus 32. So 0 °C is 273.15 K and 32 °F. The size of one Celsius degree equals the size of one Kelvin (no division). One Fahrenheit degree is 5/9 of a Celsius degree.

For an isotropic solid, the area expansion coefficient beta equals 2 alpha (twice the linear coefficient), and the volume expansion coefficient gamma equals 3 alpha. So alpha : beta : gamma equals 1 : 2 : 3. NEET expects you to know this ratio.

Specific heat capacity c is the heat needed to raise the temperature of unit mass of a substance by one Kelvin. Q equals m c delta T. Water has the highest specific heat among common substances, about 4186 J per kg per K, which is why oceans moderate climate.

Latent heat L is the heat absorbed (or released) per unit mass during a phase change without a temperature change. Q equals m L. Water has L_fusion equals 334 kJ per kg (ice to water at 0 °C) and L_vaporization equals 2260 kJ per kg (water to steam at 100 °C).

Heat flow rate dQ over dt equals minus k A dT over dx. Here k is thermal conductivity, A is cross-section, and dT over dx is the temperature gradient. Steady-state through a slab gives dQ over dt equals k A (T_hot minus T_cold) over L.

Power radiated per unit area by a black body is sigma T to the fourth, where sigma is the Stefan-Boltzmann constant equals 5.67 times 10 to the minus 8 W per m squared per K to the fourth. For a real body multiply by emissivity e. Doubling temperature multiplies radiated power by 16.