HEAT TRANSFER CONDUCTION,
CONVECTION, AND RADIATION EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
convection - ANSWER-the transfer of thermal energy by the circulation or movement of
a liquid or gas.
Describe how convection currents form. Think about a lava lamp - ANSWER-Warmer,
less dense fluids (gas or liquid) rise and more dense fluids (gas or liquid) sink.
As the less dense (or warmer) fluids rise they COOL.
Convection currents transfer thermal energy from warmer to cooler parts of the fluid.
In a convection current both conduction and convection transfer thermal energy.
Radiation - ANSWER-The transfer of energy by electromagnetic waves. This type of
energy transfer does not require the presence of molecules
Can radiation travel through solids, liquids and gases?
How does radiation travel through solids, liquids, gases? - ANSWER-Yes
Radiation waves strike a material. Some of the energy can be
1. absorbed
2. reflected
3. or transmitted
Why are gases the best at transmitting radiation? - ANSWER-Because gas particles are
further apart, the radiation energy travels through the space between the particles.
Radiation travels MORE RAPIDLY and EFFICIENTLY through GASES.
Thermal Insulators - ANSWER-Materials that are poor conductors of heat.
Material through which thermal energy moves SLOWLY
4 Examples of GOOD thermal insulators - ANSWER-1. Wood
2. Styrofoam
3. Fiberglass
4. Air
Examples of POOR thermal insulators - ANSWER-Remember..."good conductors are
poor insulators AND poor conductors are good insulators"
METALS are POOR INSULATORS
CONVECTION, AND RADIATION EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
convection - ANSWER-the transfer of thermal energy by the circulation or movement of
a liquid or gas.
Describe how convection currents form. Think about a lava lamp - ANSWER-Warmer,
less dense fluids (gas or liquid) rise and more dense fluids (gas or liquid) sink.
As the less dense (or warmer) fluids rise they COOL.
Convection currents transfer thermal energy from warmer to cooler parts of the fluid.
In a convection current both conduction and convection transfer thermal energy.
Radiation - ANSWER-The transfer of energy by electromagnetic waves. This type of
energy transfer does not require the presence of molecules
Can radiation travel through solids, liquids and gases?
How does radiation travel through solids, liquids, gases? - ANSWER-Yes
Radiation waves strike a material. Some of the energy can be
1. absorbed
2. reflected
3. or transmitted
Why are gases the best at transmitting radiation? - ANSWER-Because gas particles are
further apart, the radiation energy travels through the space between the particles.
Radiation travels MORE RAPIDLY and EFFICIENTLY through GASES.
Thermal Insulators - ANSWER-Materials that are poor conductors of heat.
Material through which thermal energy moves SLOWLY
4 Examples of GOOD thermal insulators - ANSWER-1. Wood
2. Styrofoam
3. Fiberglass
4. Air
Examples of POOR thermal insulators - ANSWER-Remember..."good conductors are
poor insulators AND poor conductors are good insulators"
METALS are POOR INSULATORS
