Development of Practical Skills in Physics

A physicist must appreciate that they don’t exist in a hypothetical universe like the mathematicians do. We make observations and measurements of real-life objects and phenomena. In order to do this we have developed a number of tools or measuring instruments, but each of these has its own limitation or resolution. This restricts how precisely we can measure things, but there is also a fundamental limit – due to the Heisenberg Uncertainty Principle! Let’s worry about that at University, for A-level you’ll need to know how to use these 5 instruments…

• Vernier callipers (precision = 0.1 mm)
• Micrometer screwgauge (precision = 0.01mm)
• Multimeters (voltmeter, ammeter, ohmmeter)
• Oscilloscopes
• Light gates and data loggers 

Socrates stated that “True wisdom is knowing you know nothing at all”, Aristotle later said that “the more you learn, the more you know you don’t know” and Thomas Young has been described as “The last man who knew everything.” This was long before the “discovery” of dark matter and dark energy, which now means physicist believe they are completely in the dark about what makes up 95% of the universe.

Physicists are therefore a humble bunch, particularly when it comes to reporting their data, and so should always state an uncertainty when presenting an experimental result. For A-level you’ll need to know how to do the following…

• Find the absolute uncertainty from a measurement or set of data
• Convert between absolute and relative (aka percentage or fractional) uncertainty
• Combine uncertainties to give an uncertainty in a derived quantity

Prior to 2015, A-level sciences in the UK had practical exams (similar to coursework), which were marked by teachers and then moderated by the exam boards. Unfortunately this system was open to abuse and has now been replaced by a minimum of 12 core practicals (6 in Y12 and 6 in Y13), which are also assessed by teachers so open to corruption. Over 99% of students will PASS the endorsement, but practical analysis skills are now examined in paper 3, so this part is what really counts.

 In order to PASS, you are supposed to have demonstrated the following 5 competencies:

• Follow written instructions
• Applies investigative approaches and methods when using instruments and equipment
• Safely uses a range of practical equipment and materials
• Makes and records observations
• Researches, references and reports