Questions to promote discussion and thinking
What the activity is for
These diagnostic questions are used for two main reasons:
- To encourage students to talk and think through their understandings of electric circuits.
- To provide the teacher with formative assessment information about the students' understandings of electric circuits.
What to prepare
- printed copies of the questions, on the support sheets
What happens during this activity
It would be a good idea to get the students to work in pairs on these questions, encouraging each pair to talk through their ideas. Collect responses from all of the pairs and discuss in a whole-class plenary.
Alternatively, the questions might be set for homework prior to the lesson, so that you have time to read through the responses.
The questions review key points relating to series circuits.
The battery potential difference is shared between two resistors connected in series: V1 is 4 volt; V2 is 5 volt; V3 is 4 volt.
The potential difference across the resistors connected in series is in proportion to their resistance (big resistance: big potential difference). V1 is between 3 volt and 6 volt: the larger share across the larger resistor.Question 3
Same reasoning as question 2: V1 is B; V2 is D; V3 is D; V4 is B.Question 4
The potential difference between a and b is zero because there is no resistance between these points, and the potential difference across R is 3 volt. With the switch open, the ammeter reads zero and the voltage between a and b is now 3 volt (The voltmeter is in effect measuring the potential difference across the supply).