CIE iGCSE Co-Ordinated Science P2.3.2 Convection Exam Style Questions Paper 1
Question
A hot metal ball is placed in a small hollow in a piece of wood. Two thermometers are placed
equal distances from the ball, one at position P and one at position Q.
Which thermometer gives the higher reading and why?
▶️Answer/Explanation
Ans : C
Question
In which of the three states of matter is convection the main method of thermal energy transfer?
(A) liquids and gases
(B) liquids only
(C) solids and liquids
(D) solids only
▶️Answer/Explanation
Ans: A
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) convection
Explanation: In liquids, heat is primarily transferred through convection, where warmer water rises and cooler water sinks, creating a circulating current.
Question
A hot water tank is fitted with two identical heaters P and Q. Heater P is fitted above heater Q as shown. The tank is full of cold water.
When only heater Q is switched on, it takes a long time to heat the tank of water to \(60^\circ C\). What happens to the cold water when only heater P is switched on?
A. All the water reaches \(60^\circ C\) in less time.
B. All the water reaches \(60^\circ C\) in the same time.
C. The water below heater P reaches \(60^\circ C\) in less time.
D. The water above heater P reaches \(60^\circ C\) in less time.
▶️Answer/Explanation
Answer: D
Explanation: When heater P is switched on, it heats the water above it first due to convection currents. Therefore, the water above heater P reaches \(60^\circ C\) in less time.
Question
A room is heated using an electric heater placed on the floor. What is the name of the process by which the heated air moves around the room?
A. conduction
B. convection
C. evaporation
D. radiation
▶️Answer/Explanation
Answer: B. convection
Explanation: Convection is the process by which heat is transferred through the movement of fluids (liquids or gases). In this case, the heated air rises and circulates around the room, creating convection currents.