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5.3. Electric Cells

You will be familiar with the standard AA battery (although they are becoming redundant in the age of modern rechargables). In Physics we often like to be very specific with our use of language – so Physicists would call this ‘a POWER CELL’ (or just ‘a cell’). When I connect multiple cells together, this is called a ‘battery’ (so 2 AA cells make a battery). Confused? To be honest, most Physicists aren’t that picky, but technically they have different circuit symbols, so it’s worth learning the difference.

 

So how exactly do batteries work? TedEd have a nice little introductory video which gives a nice little overview into how batteries work (for the IB you don’t need to worry about any of the chemistry of the internal reactions)

In this section we will look in a little more depth at power sources within circuits. The tricky part to get your head around is the idea of Internal Resistance and tackling some of the tricky MCQs that the IB sometimes ask.

 

The section is split up as follows

 

Types of Cells

There are hundreds of different types of power cell, all relying on different chemical processes for their function. In Physics, we don’t really care a huge amount about the different chemistries of these cells. We can largely group these into two categories – primary and secondary cells.

Video Lessons

Chris Doner
Cells, EMF and IR
IB Specific

Resources

IB Physics
Topic 5 Notes
IB-Physics.net
Chapter 5 Summary
IB Revision Notes
Mr. G
5.3 Teaching Notes
5.3 Student Notes
Physics and Maths Tutor
Electricity Definitions
Electricity Key Points
Electricity Detailed Notes
Electricity Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 5: Add Qs
Topic 5: Add Qs MS
Topic 5: MCQs
CUP Website Link
Freely available online
Grade Gorilla
5.2/3 (Circuits/ Cells) MCQ
Topic 5 (Circuits) End Quiz
Quick IB Specific Mixed MCQs
Mr. G
5.3 Formative Assessment
Topic 5 Summary Qs
IB Specific Questions
 

Electromotive Force

A cell is a power supply for a circuit, providing electrical energy to the charge carriers as they move around the circuit. The energy each Coulomb of charge is given (i.e. the Voltage given) is termed the Electromotive Force (EMF).

Video Lessons

Resources

IB Physics
Topic 5 Notes
IB-Physics.net
Chapter 5 Summary
IB Revision Notes
Mr. G
5.3 Teaching Notes
5.3 Student Notes
Physics and Maths Tutor
Electricity Definitions
Electricity Key Points
Electricity Detailed Notes
Electricity Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 5: Add Qs
Topic 5: Add Qs MS
Topic 5: MCQs
CUP Website Link
Freely available online
Grade Gorilla
5.2/3 (Circuits/ Cells) MCQ
Topic 5 (Circuits) End Quiz
Quick IB Specific Mixed MCQs
Mr. G
5.3 Formative Assessment
Topic 5 Summary Qs
IB Specific Questions
Physics and Maths Tutor
Internal Resisistance (AQA 1)
Internal Resisistance MS (AQA 1)
EMF & IR (AQA 2)
EMF & IR MS (AQA 2)
A-Level Qs: overlapping content
Physics and Maths Tutor
Internal Resistance (Edexcel 1)
Internal Resistance MS (Edexcel 1)
A-Level Qs: overlapping content
 

Internal Resistance

There is a common classroom experiment which allows you to calculate the internal resistance and EMF of a power source. It’s worth making sure you are confident with this experiment (the experimental setup and what the results show) as it is pretty commonly referenced. It is described in the following video.

Video Lessons

Resources

IB Physics
Topic 5 Notes
IB-Physics.net
Chapter 5 Summary
IB Revision Notes
Mr. G
5.3 Teaching Notes
5.3 Student Notes
Physics and Maths Tutor
Electricity Definitions
Electricity Key Points
Electricity Detailed Notes
Electricity Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 5: Add Qs
Topic 5: Add Qs MS
Topic 5: MCQs
CUP Website Link
Freely available online
Dr French's Eclecticon
Electrical Circuits
Electrical Circuits Solutions
Link to Dr French's Site
Extension: Pre-University Material
Grade Gorilla
5.2/3 (Circuits/ Cells) MCQ
Topic 5 (Circuits) End Quiz
Quick IB Specific Mixed MCQs
Isaac Physics
Internal Resistance
Mr. G
5.3 Formative Assessment
Topic 5 Summary Qs
IB Specific Questions
Physics and Maths Tutor
Internal Resisistance (AQA 1)
Internal Resisistance MS (AQA 1)
EMF & IR (AQA 2)
EMF & IR MS (AQA 2)
A-Level Qs: overlapping content
Physics and Maths Tutor
Internal Resistance (Edexcel 1)
Internal Resistance MS (Edexcel 1)
A-Level Qs: overlapping content
 

Additional Resources

IB Questions

A question by question breakdown of the IB papers by year is shown below to allow you to filter questions by topic. Hopefully you have access to many of these papers through your school system. If available, there may be some links to online sources of questions, though please be patient if the links are broken! (DrR: If you do find some broken links, please contact me through the site)

 

Questions on this topic (Section 5) are shown in pale green.

Use this grid to practice past IB questions topic by topic. You can see from the colours how similar the question topic breakdown is year by year. The more you can familiarise yourself with the IB question style the better - eventually you will come to spot those tricks and types of questions that reappear each year.