IB Physics Subject Guide & Exam Tips
“Higher concentration on the core topics and deeper learning of the fundamental concepts with emphasis on problem-solving questions will be central to exam preparation.”
Author: Dr. H-R Zimmermann, MScTheoretical Physicist, IBDP Physics Examiner (12 years), Math & Science Exam Preparation Coach
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PART 1
Recent syllabus changes adopted by the IBO
PART 2
A short summary with analysis based on the last Nov 2020 DP Physics SL paper 2 exam which I assessed recently in my role as IB DP Physics Examiner for this specific component.
IB DP Physics Final Examinations and Coursework Changes for 2021-2022
The current IBDP Physics syllabus, last assessment in November 2023, had to be changed and adapted recently taking into account the very special and often adverse circumstances schools, teachers, and students faced due to the Covid-19 pandemic. These remarkable changes will greatly impact the roll-out of the course in terms of teaching, learning and examination assessment.
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Important: Visit the official IBO page for the most updated information about this subject.
Check out our full list of Exam Tips & Subject Guides here.
PAPER 1
Exam Format & Structure
Remains the same for Standard Level (SL) and Higher Level (HL)
Description
Multiple-choice questions exam paper with 30 % weighting on the final grade
Changes
Weighting increased from 20 % to 30 %
Insight
Higher concentration on the core topics and deeper learning of fundamental physics concepts with emphasis on problem-solving questions will be central exam preparation.
PAPER 2
Exam Format & Structure
Remains the same for SL and HL
Description
Written short-answer and extended-response questions paper with weighting of 50%
Changes
SL: Weighting increased from 40 % to 50 %
HL: Weighting increased from 36 % to 50 %
Insight
With 50 % weight paper 2 plays a prominent role in the final physics grade.
PAPER 3
Changes
Removed from the exam
Insight
The amount of relevant assessed physics topics and material was reduced considerably with the exam performance and risk now spread to only two papers. The eliminated paper 3 was a good third independent contributor to exam success in the past.
INTERNAL ASSESSMENT (IA)
Remains unchanged with 20% weighting on the final grade.
Group 4 Coursework:
The completion of the group 4 project will not be a requirement
Insight
Topic 1 Measurement covering experimental skills and data analysis will not be assessed with exception of its usage and application in the physics Internal Assessment (IA)
Compared to the former IB DP Physics exams, the November 2020 paper 2 assessment is relatively straightforward as it covers basic classical physics problems in mechanics, thermal physics, waves, electricity and nuclear physics. It is important to recognise that some questions tackled multiple topics. Required math calculations were limited to simple arithmetic and the nuclear fission question should have been easily answered using the log-function. Note that this is an insight from a past year paper, and that with the syllabus changes (discussed above), future papers have heavier grade weightage. It would be best to prepare rigorously and expect a more challenging set of questions in the following years.
The following are types of questions that I would like to highlight to provide candidates with an insight on how to apply different Physics concepts to problem-solving.
The Unmanned Aircraft
This question dealt with an aircraft carrying a package and is hovering motionless. The horizontal blades propel air vertically downwards.
The candidate had to explain and calculate forces, equilibrium, velocity, acceleration and give the answer to an appropriate number of significant figures.
Topic/s:
Mechanics: Topic 2. 2 , Topic 2.4 & Circular Motion Topic 6.1
Candidates had to know and apply very well the different Newton laws.
Difficulty level:
Medium
Horizontally-Rotating Man
This question dealt with a man circulating in a rotor. The candidate had to draw a free-body diagram consisting of weight, friction force and the normal reaction force, calculate a non sliding minimum angular velocity and apply static friction concepts with one example calculation.
Topic/s:
Mechanics Topic 2.2, Topic 2.4 & Circular Motion Topic 6.1
Difficulty level:
Medium
Liquid-Frozen Oil Transition
This question dealt with the phase transition of liquid vegetable oil to a frozen state by transferring thermal energy from the sample at a constant rate.
Topic/s:
Thermal Physics, Topic 3.1
Thermal energy transfer, specific heat capacity and unfrozen mass had to be calculated.
Difficulty level:
Low-Medium
The Loud Speakers
This question dealt with two loudspeakers producing acoustic coherent waves which overlap with each other at a certain distance.
Topic/s:
This is a Topic 4.2 Travelling Waves question
Candidates had to deduce minimum intensity, predict varying intensities and calculate relative intensities.
Difficulty:
Low-Medium
Variable Non-Ohmic Resistor Circuit
This question dealt with an electric circuit composed of a non-ohmic component, a variable resister and a cell and adding an potential divider circuit.
Topic/s:
Topic 5.3
Resistance, the dissipated power, the range of current and describe non-ohmic behavior and circuit advantages had to be calculated
Difficulty:
Medium-High
Nuclear Decay
This question dealt with a fission reaction of uranium.
Topic/s:
Topic 7.2 Atomic, nuclear and particle physics
The student had to define binding energy, calculate mass and determine the energy released, estimate specific energy, half-life and mass
Difficulty:
Medium
Topic/s:
Thermal Physics, Topic 3.1
Thermal energy transfer, specific heat capacity and unfrozen mass had to be calculated.
Difficulty level:
Low-Medium
Mind Your Terms
- Know the difference and choose the correct term when referring to specific components of matter like molecules, particles, atoms, or nucleons
- Apply the term path difference when you calculate interference effects for coherent waves. In-phase or out-of-phase interference can be called constructive or destructive interference.
- Use the term proportionality when you describe a constant ratio of two physical variables like Voltage and Current.
Put A Label On It
Learn to draw free-body diagrams and label them in the right way, i.e. weight/W/mg are all allowed for gravitational force on the mass m.
Practice!
- Solve many appropriate electric circle questions. Most candidates are too slow when it comes to circuits.
- Try to use the log-function where appropriate
- Solve many fundamental physics problems including Multiple-Topics questions (like those described here)
Some Important Chapter-Specific Tips
- Learn to apply Newton’s second law (resultant force equal rate of change of momentum). Use if appropriate conservation of momentum and identify action equals reaction pairs as expressed by the third Newton law. Note: They will on different objects. (Chapter 2.6)
- Differentiate between static and kinetic friction and learn correctly the various concepts associated with friction. Sliding begins when force exceeds the maximum friction force. (Chapter 2)
- Recall that circular motion requires that total vector sum of all forces present has to point as a resultant force to a center of a circle. The force is centripetal, centrifugal is the wrong wording. (Chapter 6)
