Question detail
Explain how smoke entering an ionisation smoke alarm changes the current and triggers an alarm.
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
Question
Type
exam_style
Style
Topic
Hazards and uses of radioactive emissions and of background radiation
Question
Explain how smoke entering an ionisation smoke alarm changes the current and triggers an alarm.
Answer
In an ionisation smoke alarm, smoke particles disrupt the flow of ions between two electrodes, reducing the current. When the current drops below a certain threshold, the alarm is triggered, alerting occupants to the presence of smoke.
Explanation
This question tests the understanding of the operational principle of ionisation smoke alarms and the role of smoke in altering electrical current. It assesses the student's ability to connect physical processes with practical applications.
Common mistake
Misunderstanding Smoke Alarm Function
Students often think that smoke alarms only detect smoke particles without understanding the role of ionisation.
Explain that smoke entering the ionisation chamber disrupts the ionisation process, reducing current flow and triggering the alarm.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.