Question

which form of heat transfer uses direct contact?

• conduction
• convection
• radiation
• condensation

question 4
the heat transfer from moving fluids is?

• convection
• radiation
• conduction
• sublimation

Explanation:

1. For the first question: Conduction is the heat transfer method that occurs when two substances are in direct physical contact, transferring heat through molecular collisions. Convection uses fluid movement, radiation uses electromagnetic waves, and condensation is a phase change, not a primary heat transfer mode requiring direct contact.
2. For Question 4: Convection is defined as heat transfer that happens via the movement of fluids (liquids or gases), where the fluid carries thermal energy. Radiation transfers heat without a medium, conduction requires direct contact of stationary materials, and sublimation is a phase change of matter.

Answer:

1. A. Conduction
2. A. Convection