Heat Flashcards
Name some energy forms.
Light Energy, Heat Energy, Solar Energy
Which are the various situations where heat energy is used?
Cooking, Drying Clothes
Can heat energy change the state of matter? Give example.
Yes, Ice when heated becomes water, then boils to become steam which is gaseous.
Which form of energy makes ice cubes melt faster when dipped in warm water?
Heat Energy
Does heat get transferred from one substance to another? Give example.
Yes, heat energy from surrounding melts ice.
Explain transfer of heat using cooking rice as an example.
Flame -> vessel -> water -> rice
What is transmission of heat?
Transmission of heat refers to the flow of heat from one place to another.
What happens to the pot after turning off the gas stove for a while?
The pot lose heat. Heat is transferred to the surroundings, not only from the pot but also from the substances inside it. This results in heat loss to the vessel and it contents
Explain heat transmission in metals.
When heat is received at one end of a metal rod, the molecules at that end receive the heat and transfer it to the nearest molecules. This method of transmission of heat of called conduction. In solids, heat is transmitted through conduction.
What are some substances that conduct heat?
Aluminium, copper, iron
What are some substances that are not so good conductors of heat?
Wood and Glass rod
What are good and poor conductors heat?
Substances which allow heat to pass through them well by conduction are called good conductors and those substances which do not allow heat to pass through them well are called poor conductors.
To remove a hot vessel from stove do we use good or bad conductor of heat?
Bad conductor of heat. Like cloth
To make handles of cooking utensils do we use good or bad conductor of heat?
Bad conductor of heat. Like Special Plastic
To make cooking utensils do we use good or bad conductor of heat?
Good conductor of heat like aluminium and steel.
What causes heat transmission in liquid?
Heat transmission in liquids occurs in all liquids by the displacement of molecules. Heat energy is transferred when molecules move across.
What is the method of transmission of heat in gases and liquids by the displacement of molecules?
Convection is the method of transmission of heat in gases and liquids by the displacement of molecules.
What is radiation?
Radiation is the method by which heat is transmitted without the help of a medium. Heat is transmitted to all directions through radiation. Heat from the Sun reaches the Earth by radiation. White or smooth surfaces reflect radiant heat more than black or rough surfaces.
What is hot box?
A hot box is a system used to reduce the use of cooking fuel and to keep cooked food items from losing heat.
What is ice box?
Ice box is used to keep ice from melting too quickly.
How thermal expansion happens in solids, liquids and gases?
Solids, liquids and gases expand when heated and contract on cooling.
