Heat Transfer

What statement best describes convection?

• Heat is transferred through direct contact.
• Heat is transferred by electromagnetic waves.
• Heat moves in cycles within fluids (liquids and gases) due to temperature differences.
• Heat energy moves through empty space.

An example of heat transfer by radiation would be....

• Feeling the warmth of the sun.
• Boiling water in a pot.
• Touching a metal spoon heated in a pan.
• Air moving around a heated object.

The main characteristic of conduction is...

• Heat is transferred through electromagnetic waves.
• Heat is transferred through direct contact between objects.
• Heat rises because of density differences.
• Heat causes air to move in a circular pattern.

What is the main difference between conduction and convection?

• Conduction requires electromagnetic waves, while convection requires direct contact.
• Conduction occurs in solids, while convection happens in fluids (liquids or gases).
• Convection transfers heat more quickly than conduction.
• Conduction can only occur in gases, while convection happens in all states of matter.

Warm air rises during convection currents....

• Because warm air is less dense than cool air.
• Because warm air is more dense than cool air.
• Because air is a solid.
• Because heat can only move downward.

Wind and weather changes are caused by....

• The Earth’s magnetic field.
• Electromagnetic radiation.
• The rotation of the Earth.
• Convection currents in the atmosphere.

Three of these are forms of heat transfer, which one is not?

• Conduction
• Convection
• Radiation
• Reflection

Sunlight travels _______ to reach the Earth

• 1 million km
• 150 million km
• 1 billion km
• 10 million km

The Law of Conservation of Energy states what?

• Energy can be created or destroyed.
• Energy can only be transformed into heat.
• Energy is always conserved within a system.
• Energy will always be used in one direction.

When energy is transformed in a system what happens?

• Energy is conserved, but it may change forms.
• The total energy in the system increases.
• Some energy is lost and cannot be used.
• Energy is destroyed and cannot be used again.