Energy transfer by convection is usually restricted to what type of substance?

The correct answer is fluids.

Explanation:

There are 3 modes of heat transfer that happens:

1. Conduction: In this type of heat transfer, heat is transferred when there is direct contact between the two object.

2. Convection: In this type of heat transfer, heat is transferred when there is a movement of fluid (liquid or gas).

3. Radiation: In this type of heat transfer, heat is transferred when there is direct transfer of energy through space.

Hence, convection is only restricted to fluids which are liquids and gases.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.