GCSE AS-Level Physics Paper3 Tips

TIPS ON PAPER 3 UNCERTAINITIES: 1. On a measurement using a ruler take the uncertainty as 0.1 cm. 2. On a protractor take the uncertainty as 20 if you have not repeated measurements. But if you are extra careful and have repeated the measurements take the uncertainty as half of the range of measured values ( (maximum value – minimum value ) /2) .The percentage uncertainty is then calculated as the Uncertainty / (average value of the readings) x 100 % Always write your uncertainty as ±. 3. On a stop watch or measurement of time repeat your readings and take the uncertainty as half of the range. 4. On an ammeter also take half the range of fluctuations.

SIGNIFICANT FIGURES 1. If the justification of significant figures related to a calculated quantity is questioned you need to justify it as related to the significant figures of the measured values. 2. If the justification of significant figures related to a measured value is questioned you need to justify it related to the precision of the measuring instrument used.

Limitations and errors One limitation and improvement that goes with all experiments is

To improve on the limitation and improvements collect all the marking schemes from 2007 onwards and go through them .Most of them are repeated. Never write only repeating the readings and taking the average. The limitations and improvements must be related to the measurements taken and not something that you could improve by being more careful. Explain the limitation in scientific language. Remember to put the correct units (in SI system) in the final answer. On the second question remember to repeat your readings Take care of the precision and the repetitions in the readings. ALL THE BEST AND DO WELL IN THE EXAMS!!!!!!!! Mrs. Preeti M.