Download presentation

Presentation is loading. Please wait.

Published byTristen Croshaw Modified over 3 years ago

1
Review for PR 9 Pointers to note from your PR 9

2
1. Approx focal length Check correct unit (cm) You used a metre rule to measure, so it should be given to 1 decimal place!

3
2. Table of data Units – Remember that x, y, h 0, h i are all in cm – Magnification, m, does not have units (X is not a unit for magnification!!) Measured data – Data you obtain from measurements must be recorded to the appropriate decimal place based on the instrument used.

4
2. Table of data – In this experiment, y/cm, x/cm, h 0 /cm and h i /cm are all measured values. They must all be recorded to 1 decimal place. Calculated value – The only calculated value for this experiment is m! – m must follow the least number of s.f. of values used to calculate it.

5
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.5 25.030.01.21.5 30.025.51.21.1 35.023.01.20.9 40.021.31.20.7

6
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.5 25.030.01.21.5 30.025.51.21.1 35.023.01.20.9 40.021.31.20.7 2.5 1.2 2 s.f. This should be 2 s.f.

7
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.52.1 25.030.01.21.5 30.025.51.21.1 35.023.01.20.9 40.021.31.20.7

8
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.52.1 25.030.01.21.51.3 30.025.51.21.10.92 35.023.01.20.9 40.021.31.20.7 0.9 1.2 1 s. f. 2 s.f. This should be 1 s.f.

9
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.52.1 25.030.01.21.51.3 30.025.51.21.10.92 35.023.01.20.90.8 40.021.31.20.7

10
Example of table y/ cmx/ cmh 0 / cmh i / cmm 20.042.01.22.52.1 25.030.01.21.51.3 30.025.51.21.10.92 35.023.01.20.90.8 40.021.31.20.70.6 The number of sig fig is dependent on those particular values used to calculate that one specific value of m.

11
3. Graph S – Scale (data points need to cover at least 5 big squares horizontally and 6 big squares vertically) P – Points are correctly plotted to get this point L – A good best fit line is drawn (also depends on whether the line is neat) A – Label axes properly!

12
3. Graph C – Choose points OTHER THAN your own data points. – Write coordinates to the precision of the graph paper (don’t round up to 3 s.f.!! Leave it to the most precise value you can determine in the graph) T – Triangle has to be big enough! – Use dotted lines!

13
Example of Graph First data point Last data point These points must be more than 5 big squares apart Similarly for vertical, the first and last data points must be more than 6 big squares apart

14
4. Precaution Must have two parts: – Action taken – How it helps to make your results better – Which particular reading does it improve Example: – Switch off the lights so that the image formed will be clearer and thus, the determination of x will be more accurate.

15
5. Sources of error Must have 2 parts – Describe the difficulty you faced in the experiment – State which measurement it affects (measurement of x, y, or h) Example 1: – It is difficult to determine when the sharpest image is formed. The image remains focused over a range of x values. Therefore, the error in the measurement of x values is significant.

16
5. Sources of error Example 2: – The precision of the ruler is only 0.1 cm, but the smallest h i reading required to be measured is 0.4 cm. The percentage of uncertainty is about 25%. Thus, the precision of the ruler causes a significant source of error.

17
Bear these points in mind for Practicals next year! Study hard for EOY! Check your marks on SDMS!

Similar presentations

OK

1.2.6-11Uncertainty and error. 1.2.7 Distinguish between precision and accuracy Accuracy is how close to the “correct” value Precision is being able to.

1.2.6-11Uncertainty and error. 1.2.7 Distinguish between precision and accuracy Accuracy is how close to the “correct” value Precision is being able to.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on recent natural disasters in india Ppt on object-oriented technologies Ppt on content development definition Seminar ppt on secure atm by image processing Ppt on principles of peace building review Poster template free download ppt on pollution Ppt on latest technology in computer Ppt on credit policy document Ppt on coda file system Ppt on eia report 2016