---

3.7 A little more on potential difference - effect of two resistors in series - explaining and verifying by calculation, how the potential difference is split between resistances in series

Explaining and verifying by calculation, how the potential difference (p.d.) is split (divided, shared) between resistances in series i.e. the effect of two (or more) resistors in series

The circuit 41 shows two resistors wired in series, so how is the total p.d. divided or shared between the two resistance wired in series.

This circuit can be used to investigate and confirm the correctness of the following theoretical calculations.

On the right is shown what happens to the p.d. going clockwise around the circuit (direction of convention current).

 

The potential store of the battery raises the potential difference of the charge to 12.0 V.

The total resistance = 10.0 + 5.0 = 15.0 Ω (you can add resistors up if wired in series)

Therefore the current flowing round all of this series circuit

= I = V / R_total = 12.0 / 15.0 = 0.80 A

 

As the charge passes through the 1st resistor R₁, it loses energy and the p.d. falls by 8 V to a p.d. of 4 V.

Calculation to confirm this:  V₁ = I x R₁ = 0.80 x 10.0 = 8.0 V

 

As the charge passes through the 2nd resistor R₁, it loses energy again and the p.d. falls by 4 V to a p.d. of 0 V.

Calculation to confirm this:  V₂ = I x R₂ = 0.80 x 5.0 = 4.0 V

 

As long as there is a complete circuit, the process repeats itself through any number of resistors.

What is clear is the total p.d. for the circuit is split into a p.d. ratio identical to the resistor ratio.

V₁ : V₂ is the same ratio as R₁ : R₂

 

You can also say that since E = QV, twice as much energy is released by resistor R₁ (p.d. 8 V) than R₂ (p.d. 4 V) for the same total current, the same total charge transferred, but the lower the p.d. the less potential energy carried by the charge.

 

INDEX of electricity section 3 notes on current, voltage, resistance, energy & charge transfer in circuits including Ohm's Law investigations

---

Key points about electric circuits in physics courses - fall in p.d. across resistors in series

Information sources for Doc Brown's key points: IGCSE-GCSE physics are based on textbooks & syllabus-specifications for students taking the UK AQA, Edexcel, OCR 21st Century Science, OCR Gateway science suite, WJEC, CCEA and CIE GCSE physics 9-1 level science examinations.

Keywords, phrases and learning objectives for electricity topics involving resistances in series

Be able to explain and verifying by calculation (and experiment), how potential difference is split and shared divided between resistances in series.

Be able to describe the effect of two resistors in series on the p.d. across these resistors wired in series.

---

WHAT NEXT?

TOP of page

INDEX for physics electricity section 3 notes on current, voltage, resistance, energy & charge transfer in circuits

ALL my electricity and magnetism notes

email doc brown - comments - query?

INDEX of all my PHYSICS NOTES

---

Basic Science Quizzes for UK KS3 science students aged ~12-14, ~US grades 6-8

Biology * Chemistry * Physics for UK GCSE level students aged ~14-16, ~US grades 9-10

Advanced Level Chemistry for pre-university age ~16-18 ~US grades 11-12, K12 Honors

Find your GCSE/IGCSE science course for more help links to all science revision notes

INDEX of electricity section 3 notes on current, voltage, resistance, energy & charge transfer in circuits including Ohm's Law investigations

SITEMAP Website content © Dr Phil Brown 2000+. All copyrights reserved on Doc Brown's physics revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Exam revision summaries and references to GCSE science course specifications are unofficial.

---

Based on the syllabus-specifications for students taking the IGCSE/GCSE level physics examinations summary revision notes and key points on investigating how a total p.d. is split across  for students taking the AQA igcse/gcse physics notes on investigating how a total p.d. is split across , Edexcel gcse physics notes on investigating how a total p.d. is split across ,  OCR 21st century GCSE physics notes on investigating how a total p.d. is split across , OCR gateway GCSE physics notes on investigating how a total p.d. is split across , WJEC gcse physics notes on investigating how a total p.d. is split across , CCEA gcse physics notes on investigating how a total p.d. is split across  for students taking CIE Cambridge igcse physics, or any other GCSE or IGCSE level physics exams notes on investigating how a total p.d. is split across , useful for US grade 9-10 physics courses, Explaining the importance of how to calculate potential differences across resistors wired in series  in GCSE level physics, What you need to know about how to calculate potential differences across resistors wired in series  for GCSE level physics, Explaining what is the use of how to calculate potential differences across resistors wired in series  knowledge in GCSE level physics, Examples of how to calculate potential differences across resistors wired in series  explained when studying GCSE level physics, What is the significance of how to calculate potential differences across resistors wired in series  in GCSE level physics, Describing and explaining the theory of how to calculate potential differences across resistors wired in series  when studying GCSE level physics, revision notes for how to calculate potential differences across resistors wired in series  in exams, online exam help for how to calculate potential differences across resistors wired in series , revision notes for how to calculate potential differences across resistors wired in series , what do I need to learn about how to calculate potential differences across resistors wired in series  for by GCSE physics exam? revision summary for how to calculate potential differences across resistors wired in series , help in teaching how to calculate potential differences across resistors wired in series , learning notes for how to calculate potential differences across resistors wired in series , help to understand the how to calculate potential differences across resistors wired in series  topic in preparation GCSE physics exam question, how to prepare for questions involving how to calculate potential differences across resistors wired in series  in a GCSE physics examination?