Heat and Thermodynamics II - SS1 Physics Past Questions and Answers - page 3
Which of the following heat transfer mechanisms does not require a medium?
Conduction
Convection
Radiation
None of the above
Heat transfer through direct contact between particles of a substance is called:
Conduction
Convection
Radiation
Insulation
Which of the following heat transfer mechanisms involves the movement of fluid or gas?
Conduction
Convection
Radiation
Conduction and convection
Which heat transfer mechanism occurs through electromagnetic waves?
Conduction
Convection
Radiation
Both convection and radiation
Which of the following materials is a good conductor of heat?
Wood
Plastic
Glass
Metal
Heat transfer in a pot of boiling water primarily occurs through:
Conduction
Convection
Radiation
Both conduction and convection
Explain the process of conduction and give examples of conduction in everyday life.
Conduction is the transfer of heat through direct contact between particles of a substance. It occurs when the particles gain energy and vibrate, transferring that energy to neighbouring particles. This process continues until thermal equilibrium is reached.
Examples of conduction in everyday life include:
-
Touching a hot stove and feeling the heat transfer from the stove to your hand.
-
Placing a metal spoon in a cup of hot coffee, where heat is conducted from the coffee to the spoon.
-
Walking barefoot on hot sand, where heat is conducted from the sand to your feet.
Describe the process of convection and provide real-world examples.
Convection is the transfer of heat through the movement of fluid or gas. It occurs when warmer particles rise and cooler particles sink, creating a cycle of fluid motion. Convection allows for the transfer of heat over larger distances.
Real-world examples of convection include:
-
Boiling water in a pot, where heat is transferred from the bottom of the pot to the water through convection currents.
-
Heating a room with a radiator, where warm air rises, creates convection currents that distribute heat throughout the room.
-
Ocean currents, where warm water near the equator rises and cooler water from the poles sinks, create a global convection system.
The first law of thermodynamics is also known as the law of:
Conservation of Energy
Conservation of Mass
Conservation of Momentum
Conservation of Entropy
The first law of thermodynamics states that energy cannot be created or:
Destroyed
Transformed
Transferred
Dissipated