Thermal Energy III - JSS2 Basic science Past Questions and Answers - page 1
What is convection?
A process of heat transfer in fluids
A process of heat transfer in solids
A process of heat transfer through electromagnetic waves
A process of heat transfer through direct contact
Where does convection primarily occur?
Only in solids
Only in gases
Only in liquids
In fluids (liquids and gases)
What happens to warmer particles in convection?
They sink
They rise
They remain stationary
They disappear
How do cooler particles behave in convection?
They rise
They sink
They evaporate
They condense
What analogy can be used to explain convection?
A burning candle
A boiling pot of water
A metal rod heating up
A block of ice melting
Where are convection currents crucial for heat distribution?
Only in the atmosphere
Only in oceans
In both the atmosphere and oceans
Only in solids
What role do convection currents play in weather patterns?
No role
Minor role
Major role
Only in extreme weather
How does convection help in redistributing heat in the Earth's atmosphere and oceans?
Convection helps in redistributing heat by creating vertical currents in fluids. Warmer fluids rise, carrying heat energy upwards, while cooler fluids sink, replacing them. This circulation helps regulate temperatures, influencing weather patterns and ocean currents.
Can you provide an everyday example of convection and explain how it works?
An everyday example of convection is boiling water on a stove. As the water heats up at the bottom of the pot, it becomes less dense and rises to the surface. Meanwhile, cooler water near the surface moves downwards to replace it. This continuous circulation of water helps distribute the heat evenly throughout the pot, causing it to boil.
Why is understanding convection important in various fields like meteorology and oceanography?
Convection plays a significant role in redistributing heat energy, which in turn affects temperature variations in the atmosphere and oceans. By understanding convection, scientists can better predict and understand weather events, ocean circulation patterns, and their impacts on ecosystems and human activities.