CIE iGCSE Co-Ordinated Science P2.3.2 Convection Exam Style Questions Paper 2
Question
In a room, hot air above a heater rises and is replaced by cool air that falls.
What is the name of this process, and how does the density of the hot air compare with the density of the cool air?
▶️Answer/Explanation
Ans : D
Question
One cause of air movement in the atmosphere is convection.
Which statement describes air that rises in the atmosphere due to convection?
(A) It is cooler and less dense than the surrounding air.
(B) It is cooler and more dense than the surrounding air.
(C) It is warmer and less dense than the surrounding air.
(D) It is warmer and more dense than the surrounding air.
▶️Answer/Explanation
Ans: C
Question
In a room, hot air above a heater rises and is replaced by cool air that falls. What is the name of this process, and how does the density of the hot air compare with the density of the cool air?
| Process | Density of hot air | |
|---|---|---|
| A | conduction | greater than cool air |
| B | conduction | less than cool air |
| C | convection | greater than cool air |
| D | convection | less than cool air |
▶️Answer/Explanation
Answer: D
Explanation: The process described is convection, where hot air rises because it is less dense than cool air. Cool air, being denser, falls to replace the rising hot air.
Question
An electric kettle is switched on and the temperature of the water in it increases to 60°C. What is the main method of heat transfer within the water?
A. boiling
B. conduction
C. convection
D. radiation
▶️Answer/Explanation
Answer: C
Explanation: In a kettle, heat is transferred through the water mainly by convection. Hot water rises, and cooler water sinks, creating a convection current that distributes heat throughout the water.