Physics A

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Physics A is the more popular choice between the two physics options available at IB (for those not taking both), particularly because of the greater relevance of its content to other subjects. It is commonly taken together with Physics B and Mathematics, for those who are certain that will be specialising in Physics or Astrophysics in Part II. It is also common to take either double physics (A & B) with another unrelated subject or indeed combine single physics (A or B) with other subjects. This would allow one to keep their options open for Part II, but those who are not taking IB Maths would have to attend the Mathematical Methods course in Michaelmas term to build the mathematical foundations for the concepts that will be covered in Physics A.  Both Physics A & B must be taken at the IB level to take it as a Part II course or as a half subject as part of the Physical Sciences option. Lectures are usually at 11 am on Mondays, Wednesdays and Fridays.   Physics A transitions rather smoothly from IA Physics, starting with Oscillations, Waves and Optics (OWO – still not as questionable as PoO) which begins by covering most of the content from the IA Oscillations course before progressing to new content. This course is lectured concurrently with the Experimental Methods course. The course then continues with Quantum Physics, arguably the highlight of the course, which is then lectured throughout Lent. Finally, the course concludes with Condensed Matter Physics which draws upon ideas from earlier courses. Although the course is designed to be self-contained, those also taking Physics B and Maths will definitely be able to appreciate some of the concepts covered on a deeper level.   In general, most lecture notes tend to be filled (without blanks for you to fill in), either in the form of slides or handouts, but each course is lectured differently with each lecturer referring to the lecture notes to differing extents. A short summary of each lecture course is as follows:   Michaelmas (OWO & Experimental Physics):
  • Oscillations, Waves and Optics: The course begins with oscillations and essentially revises the entirety of the IA Oscillations and Waves courses before introducing extensions to existing concepts such as response factors and polarisation. Then, it continues with waves where students are introduced to sound waves and dispersion for the first time. The course concludes with optics, which introduces Fresnel and Fraunhofer diffraction, delves deep into how Fourier Transforms can be applied to Fraunhofer diffraction, and briefly covers interferometry. Most of what is covered is derived rigorously, and the accompanying example questions provide many opportunities for one to convince themselves of the validity of the concepts presented.
  • Experimental Methods: This is lectured simultaneously with the Monday and Friday lectures covering OWO, and the Wednesday lecture covering Experimental Methods. The aim of the course is to provide the theoretical background for the practical sessions and cover important concepts necessary in experimental work at higher levels. The course heavily uses electrical circuits, in particular Op-Amps, as a subject. As such, it can feel like an electronics course rather than an experimental methods course at times. The lecture slides alone are not very helpful in building understanding, hence clarifying concepts in supervisions is key to understanding what is being covered.
  Lent (Inorganic):
  • Quantum Physics (QP): This course, spanning a mammoth 24 lectures, will be the first time you encounter QP properly (having been briefly introduced to some related concepts in the IA Waves course). The course builds foundations well, by first motivating the need for QP with a brief discussion of historical developments, before moving onto Wavefunctions and the Schrodinger Equation. It then covers potential wells (and bound and unbound particles) from IA Waves much more rigorously. Following this, you will be introduced to operators in physics for the first time, which sets the stage to derive many important results such as the uncertainty principle, the orbitals of electrons in a hydrogen-like atom and two-particle systems. Finally, you are introduced to Spin and its implications on particle exchange (which gives rise to the Pauli Exclusion Principle amongst other things).
  Easter (Biological):
  • Condensed Matter Physics (CMP): The final lecture course consists of just 10 lectures, before examinations begin and builds very quickly on the concepts in the QP, so you must be solid on everything covered in Lent before Easter term begins. The course begins by introducing the concept of phonons (not a spelling mistake!), and covers theoretical models used to explain trends in properties such as heat capacity and thermal conductivity of insulators and conductors. The course concludes by deriving the band structure. This is then used to differentiate between conductors, insulators, and semiconductors, and explain some of the properties of semiconductors.


The content covered in supervisions will obviously vary from supervisor to supervisor, but in general you can expect for supervision problems to take longer to solve than they have in IA. Problems are usually graded from A to C, with A indicating a simple problem meant to test basic understanding, and C implying the problem is significantly challenging. Most tripos questions would probably fall somewhere between B and C. There are usually also a few computational problems on the example sheet, which can be solved using content covered in IA Scientific Computing. These problems are mainly on the supervision sheet to extend your understanding (as opposed to providing exam practice) so don’t be put off by their difficulty. It is worth highlighting that some courses’ supervision problems require content not strictly covered in the lecture notes. Do take note of these questions, because this content may very well appear in the examinations.


As in the case for many Part IB subjects, there is a practical session every week. This can either be a continuous 7h 45min slot (with a break for lunch) on one day, or two shorter sessions distributed over two days depending on your slot allocation. You have some ability to choose your practical slot: It is likely that during the induction briefing at the start of the year you will be handed a piece of paper on the way in. This is randomised and will decide your practical slot, but you can make mutual swaps with others before handing this piece of paper back with your name on it. After this point, it is extremely difficult to change your practical slot.   Practicals are like IA in that marking is formative with standard credit, but there is a graded scientific report due shortly after Michaelmas term ends (or you can instead choose to submit one after Lent term ends if you are taking single physics – refer to the lab manual for more detail). Practicals in Michaelmas don’t necessarily follow the Experimental Methods course closely, but will draw upon much of the course’s content, particularly when it comes to Op Amps.   Lent term gets much busier. If you are taking double physics students, you will be assigned to a group at the start of Lent and you will be expected to work together on: a scientific poster on a topic in the course syllabus that you will present at a poster session at the end of the term an extended investigation at the end of the term that will involve using the techniques learnt throughout the Lent practicals to investigate an open problem (e.g., what is the wavelength of a given laser). You then prepare a group presentation detailing your findings. This is also due at the end of the term.   If you are taking Physics A as a single physics option, you don’t have to do the extended investigation, but will still have to participate in a poster session. Practicals in Lent follow the same format as in Michaelmas vis-à-vis standard credit, but you can choose 3 out of about 5 available practicals to perform in weeks 3, 4 and 5 if you are doing double physics. If you are doing single physics, the choice of practicals has some restrictions which are detailed in the lab manual. Choosing your practical is done at the start of the practical session on a first-come-first-served basis where the limiting factor is the number of setups available for that experiment. It has been the case at least this year that the extended investigation was related to optics, if this remains the case next year, doing the optics experiments would probably provide the most benefit for those doing the extended investigation.

Revision and Exams

In addition to the assessed practical coursework (which forms 25% of the overall grade), there are two 3-hour papers at the end of the year. There is no choice of question, but the content is usually split such that Paper 1 covers Experimental Methods and QP, while Paper 2 covers OWO and CMP. There are 5 short questions in Section A, 3 to 4 long questions and either essay or brief notes questions forming the remainder of the marks.   Past papers are the main resource for revision. The TIS has papers ranging all the way back until 1995 so there is no shortage of these. As for suggested answers, the TIS has these for certain years, though some supervisors provide unofficial solutions for other years as well. The brief notes and essay questions can be prepared for by preparing essay plans in advance. There is a somewhat limited set of essay/brief notes questions that can be asked, hence it is possible to work through a few years’ worth of questions and find that you have covered a decent chunk of examinable content that can be tested in the form of essay questions.  

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