## How to do well for qualitative structured questions in A Level Physics

### What are Physics qualitative questions?

Qualitative questions are structured questions that require you to define, describe, and explain phenomena.

Understanding physics concepts and how to apply each formula won’t be enough to do well for H2 Physics. Instead of answering in our own words based on our understanding of the physics concepts, we must be able to answer qualitative questions with the required scientific terms, keywords, and phrases to score.

In our Physics Notes, we compiled many commonly asked qualitative questions for all topics and the answers to tackle them comprehensively with the correct scientific terms, keywords, and phrases.

### Who are we?

At alevelnotes.org, we are A Level graduates who love making notes. Over the years, we have compiled different Physics resources together to build a comprehensive and rigourous set of notes.

## Join us to further improve these notes to build the most comprehensive and useful set of notes for A Levels together.

Here are some considerations when answering qualitative questions in general.

### Physics Definition Questions

This is the first type of qualitative questions tested in the A Levels. It requires students to define a certain concept and phenomenon with the scientific terms and keywords. Students often lose marks when they miss out even one keyword or do not have the exact keywords and phrases in their answers.

Useful techniques in tackling definition questions

1. Remember (memorise) them
• In our Physics Notes, the first segment of every topic will cover a list of definitions that have been tested in past year A Level papers, are commonly tested in school examinations, part of the syllabus requirements, or are likely to be tested in future examinations
• You can use the definitions list as a starter – memorise the keywords and key phrases you need to have to define the term or phenomenon
2. Explain physics formulas in words
• Many physics definitions can be ‘translated’ from physics formulas by breaking each part down
• Take “Newton’s Law of Gravitation” for example:
• Force of attraction between two point masses is directly proportional to the product of their masses and inversely proportional to the square of their separation
1. Group similar definitions together
• Many physics definitions are very similar or are sub-sets of each other
• Take “Electric Potential Energy” and “Electric Potential” for example:
• Electric Potential Energy – Electric potential energy at a point is the work done by an external agent on a charge to move the charge from infinity to that point
• Electric Potential – Electric potential at a point is the work done per unit positive charge by an external agent to move a point charge from infinity to that point

### Physics Qualitative Questions

Along with calculation questions, this type of questions has the bulk of the marks in H2 Physics papers. And they are the ones that most students will lose marks in because they come in all styles and are unpredictable. However, by scanning through all the Preliminary Examination questions and A Level Papers, there are some types of questions that are commonly asked. Before diving straight into each topic, let’s run through some general techniques you can use to answer qualitative questions.

In explaining and describing certain phenomena, we can consider the following techniques in general.

Useful techniques in tackling other qualitative questions

1. Explain physics formulas and equations in words
• Take this question for example: If Young’s double-slit experiment were conducted underwater, how would the observed interference pattern be affected?
• The speed of electromagnetic radiation underwater will be much slower than that in a vacuum. The wavelength of the wave will decrease and fringe spacing of observed interference pattern will decrease.
1. Utilise physics laws and concepts
• Many questions can be answered by referring to the related physics laws and concepts
• We quote the physics law / concept involved and apply it to the phenomenon
• Take a question on explaining magnetic flux in a coil for example:
• Faraday’s law of magnetic induction – Induced emf is directly proportional to the rate of change of magnetic flux linkage
• Lenz’s law – Induced emf is in a direction so as to produce effects to oppose the change producing it
• Answer: When coil is pulled out of magnetic field, magnetic flux linkage through coil decreases, thus according to Lenz’s law, the induced emf will produce an induced current in a direction to produce effects to oppose this decrease and thus flow counterclockwise to produce its own magnetic field out of the page.
1. Kinematics considerations
• What is the magnitude of velocity? What is the direction?
• Acceleration magnitude and direction? Does it oppose the direction of velocity?
1. Force considerations
• Consider all the forces acting on the object / system: gravitational force, upthrust, contact force, friction, etc
• Consider the resultant force. Is the system in equilibrium? What is the direction of resultant force?
2. Energy considerations
• Apply conservation of energy and explain it in words
• Describe the conversion of energy from one type to the other. For example, how gravitational potential energy of a pendulum is converted to kinetic energy, and thus the rise in velocity.