Preparing For A Practical Exam

A Physics Practical Exam will test you on your ability to correctly use standard Physics apparatus to make and correctly record measurements. You will generally not need to be able to recall equations or definitions from memory.

1. Revision

Look at the past practical experiments that you have conducted. Most practical exam questions will be similar (though not identical) to these.

2. Precision of Instruments

Many marks will be gained from simply recording all values to the correct precision of the instrument being used.

(A) Record to smallest division on scale: Ruler & Protractor

• • • • Precision of Ruler: 1 mm
      • Precision of Protractor: 1°

eg. a length (as measured with a ruler) should never be recorded as 60 cm or 62.25 cm. (Theses should be 60.0 cm and 62.3 cm respectively.)

(B) Record to half of smallest division on scale: All other Measuring Instruments with scales.

measuring cylinders, voltmeters, ammeters, newton-meters, etc.

note: the precision of these should not just be memorised. For example, different voltmeters will have different precisions depending on their scale.

(C) Digital Scales should be recorded to their full precision with the following three exceptions:

• • • • stopwatch: record to 0.1 s
      • digital callipers: record to 0.1 mm
      • digital micrometer screw gauge: record to 0.01 mm

To help remember this understand that ruler, callipers and micrometer each just add one extra digit of precision:

ruler to 1 mm, callipers to 0.1 mm and micrometer to 0.01 mm

3. Recording Values

Ensure all readings are recorded clearly to the appropriate precision and have units.

If you have many sets of readings then they should be put into a table.

Try and take the readings as carefully as you can, but also do try to get the readings done as quickly as possible so that you have more time to answer questions and analyze the data.

4. Plotting a Graph

Graph plotting is a usual requirement of a Practical Exam. Make sure you are familiar with expectations of a graph.

5. Don’t Be afraid to Ask For Help

If you think the apparatus is not perfect , ask for help! The teacher will check for you and fix anything if needed. Sometimes things just stop working, even though they may have been checked before the start of your shift.

If nothing is wrong with the apparatus, your teacher will tell you so and you will not be penalized (but you have learnt that it is therefore you doing something wrongly!).

There is no point telling the teacher at the end of the practical that you think your apparatus was faulty.

Good Luck!!!