Difficulty: Easy
Correct Answer: it blows air through the radiator when necessary
Explanation:
Introduction / Context:
Radiator fans (engine-driven or electric) maintain airflow across the radiator core when ram-air from vehicle motion is insufficient. This prevents coolant temperatures from exceeding limits in traffic, at idle, or under high load at low speed.
Given Data / Assumptions:
Concept / Approach:
The radiator rejects heat from the coolant to ambient air. The fan’s purpose is to force or pull air through the radiator fins, sustaining the heat transfer rate independent of vehicle speed.
Step-by-Step Solution:
Verification / Alternative check:
Fan activation at idle coincides with rising coolant temperature; switching off the fan typically causes temperature to climb, confirming its role.
Why Other Options Are Wrong:
Common Pitfalls:
Missing shrouds which greatly reduce fan effectiveness; incorrect fan rotation; failed relays/sensors preventing timely activation.
Final Answer:
Discussion & Comments