Heat: Revision.3

What is heat?

• The transfer of energy from a system with lower temperature to one with higher temperature.

• The transfer of energy from a system with higher temperature to one with lower temperature.

• The transfer of energy within a system without any temperature change.

• The transfer of energy that only occurs in solids.

Which method of heat transfer does not require a medium?

• All of the above

• Conduction

• Convection

• Radiation

In which state of matter is thermal conduction most efficient?

• Solids

• Gases

• Liquids

• Plasma

What causes convection currents in fluids?

• The presence of a vacuum

• The movement of electromagnetic waves

• The vibration of atoms and molecules

• The difference in density due to temperature changes

Which of the following is an example of conduction?

• A metal spoon getting hot in a hot drink

• Feeling warmth from the Sun

• Sea breezes

• Boiling water in a pot

What happens to the density of a fluid as it is heated?

• It remains the same

• It increases

• It decreases

• It fluctuates randomly

Which of the following is an example of convection?

• A metal spoon getting hot in a hot drink

• Boiling water in a pot

• Feeling heat from a campfire

• Ironing clothes

What type of radiation is primarily involved in heat transfer?

• Gamma rays

• Infrared radiation

• Visible light

• Ultraviolet radiation

What is the peak wavelength in a radiation curve?

• The wavelength at which the intensity of radiation is lowest

• The longest wavelength emitted by an object

• The wavelength at which the intensity of radiation is highest

• The average wavelength of all emitted radiation

What happens to the peak wavelength as the temperature of an object increases?

• It shifts to shorter wavelengths

• It disappears

• It shifts to longer wavelengths

• It remains the same