NCERT Solutions for Class 11 Physics Ch-10: Thermal Properties of Matter

Answer: Specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of a unit mass of the substance by one degree (Celsius or Kelvin). Its SI unit is joule per kilogram per kelvin (J kg⁻¹ K⁻¹).

Answer: Latent heat is the amount of heat absorbed or released by a substance during a change of state at constant temperature, without any change in temperature. Its two main types are latent heat of fusion (associated with melting/solidifying) and latent heat of vaporization (associated with boiling/condensation).

Answer: Conduction is the transfer of heat through a medium without the actual movement of the material particles, typical in solids. Convection is the transfer of heat through the actual movement of fluid particles (liquids or gases) carrying thermal energy. Radiation is the transfer of heat through electromagnetic waves, which does not require any medium and can occur even through vacuum.

Answer: Linear expansion refers to the increase in length of a solid on heating (governed by the coefficient of linear expansion α), area expansion refers to the increase in surface area (coefficient β ≈ 2α), and volume expansion refers to the increase in volume (coefficient γ ≈ 3α), with the coefficients related approximately as α : β : γ = 1 : 2 : 3.

Answer: Newton's law of cooling states that the rate of loss of heat of a body is directly proportional to the difference in temperature between the body and its surroundings, provided this difference is small, i.e., -dT/dt ∝ (T − T0), where T0 is the surrounding temperature.