Removing bulbs

Removing bulbs

Auto-markingPencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about electric circuits.
 
Why is it important to know this? Every day we use electricity for such things as heating, lighting and cooking. Knowing what may stop an electrical circuit working is useful for working out why an appliance is not working, or to build electric circuits ourselves.
electric circuit
A box has four bulbs screwed into sockets on its top. A circuit diagram of this is drawn above.

Question

a)  When Bulb A is removed, all the bulbs go out.
     Which is the Bulb A socket?

    • 1

    • 2

    • 3

    • 4

Question

b)  When Bulb B is removed, no other bulbs go out.
     Which is the Bulb B socket?

    • 1

    • 2

    • 3

    • 4

Question

c)  If the bulb in Socket 2 is removed, what will happen?

    • Nothing; the remaining 3 bulbs will light up.

    • Only the bulbs in Sockets 3 and 4 will light up.

    • Only the bulbs in Sockets 1 and 4 will light up.

    • None of the bulbs will light up.

Task administration: 
This task can be completed with pencil and paper or online (with auto-marking).
Level:
5
Curriculum info: 
Science, Knowledge, Physical World
Keywords: 
physics concepts, energy, electricity, circuits
Description of task: 
Students use a circuit diagram to answer questions about how removing bulbs affects the other bulbs in the circuit. Assessment focus: Electrical circuits
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask
 
Capability: Interpret representations
This resource provides opportunities to discuss interpreting formal science representations such as circuit diagrams.
Science capabilities: 
Interpret representations
Answers/responses: 
 
 

Y9 (11/1996)
a) D (4) moderate
b) C (3) moderate
c) B (Only the bulbs in Sockets 3 and 4 will light up) moderate
Teaching and learning: 
Students could practise putting lightbulbs in circuits.  A circuit is a closed loop made up of electrical elements such as light bulbs that gives a return path for the current. Circuits that are incomplete have a gap and the current cannot flow through the elelments. Students will need to decide the number of loops in their circuit. Students could then predict what will happen when a loop is incomplete or complete and then test their theory, e.g., complete curcuits allow the light bulbs to glow and incomplete circuits do not.
Diagnostic and formative information: 
  Common errors
a) Option C (3) chosen by 31% of the students.
c) Option A (Nothing; the remaining 3 bulbs will light up.) chosen by 21% of the students.