Physics 2002 JAMB Past Questions - Question 23: The radiator of a motor car is cooled by

Correct Answer

B

Explanation

The radiator of a motor car is typically cooled by a combination of air and a liquid coolant, usually water and antifreeze. Here's how the cooling system works:

1. Liquid Coolant: A mixture of water and antifreeze is circulated through the engine to absorb heat generated during combustion. The coolant helps maintain the engine's temperature within an optimal operating range and prevents it from overheating.

2. Radiator: The radiator is a heat exchanger made up of a network of small tubes and fins. It is usually located at the front of the car. As the hot coolant flows through the radiator, the heat is transferred from the coolant to the surrounding air.

3. Fans: Electric fans, or sometimes mechanical fans, are often used to help improve airflow through the radiator, especially when the car is moving slowly or stopped. They can be controlled to turn on or off as needed to maintain the right temperature.

4. Airflow: As the car moves, air is naturally drawn through the front grille and over the radiator, which helps to dissipate the heat from the coolant. This process is known as forced convection cooling.

5. Thermostat: A thermostat is a device that helps regulate the engine's temperature. It opens and closes to control the flow of coolant between the engine and the radiator, ensuring that the engine operates at the proper temperature.

In summary, the radiator is primarily cooled by the combination of the liquid coolant circulating through it and the airflow passing over it as the car moves. This cooling system is essential to prevent the engine from overheating and to maintain its efficiency and longevity.