Fill in the blanks: The thermal expansion of solids can be classified into ___, ___, and ___.

Linear expansion, superficial expansion, and cubical expansion

True or False: The coefficient of linear expansion is negative for all solids.

False. The coefficient of linear expansion is positive for most solids except for some materials like plastic, which have a negative coefficient.

What is the relationship between the coefficient of linear expansion (α) and the coefficient of superficial expansion (β)?

The relationship is given by β = 2α, meaning that the coefficient of superficial expansion is twice that of linear expansion.

What happens to the density of a solid when it is heated, and why?

When a solid is heated, its density typically decreases because its volume increases due to thermal expansion while its mass remains constant.

What is the formula for calculating the specific heat (s) of a substance?

The formula is Q = m × s ×Δθ, where Q is the heat supplied, m is the mass, and Δθ is the change in temperature.

What is the relationship described by Stefan's Law of Radiation?

Stefan's Law states that the amount of energy radiated per unit area per second is directly proportional to the fourth power of the absolute temperature (E ∝ T⁴).

Fill in the blank: The amount of radiant energy emitted per second from a unit area of a radiating surface is called ___ power.

Emissive

What happens to the energy distribution of black body radiation as the temperature increases?

As the temperature increases, the total energy emitted by a black body increases and shifts towards shorter wavelengths.

Fill in the blank: The process in which heat is transferred through electromagnetic waves is called ___.

Radiation

If the length of a rod at 0°C is ℓ₀, what is its length at T°C given the coefficient of linear expansion α?

The length at T°C is given by ℓ = ℓ₀(1 + αT).

Why do lakes freeze top-down instead of bottom-up?

Water above 4 °C sinks; below 4 °C becomes less dense, stays on top and freezes.

True/False

In forced convection, buoyancy drives the flow.

False

 (external agency like fan/pump). Natural convection is buoyancy-driven.