For those resitting AS EMPA

Here are some practice questions, to complete, we will go through these on Tuesday 2pm in the library (come at 2.30 if you have a period 5 lesson) ready for the exam the next day in the morning 830 am.
Ms H

AS EMPA practice questions

Results from Task 2

V1 /V	V2 /V	V3 /V	V3 /V	V3 /V	V3  /V average
4.03	2.00	3.73	3.71	3.72	3.73
3.50	1.76	3.28	3.26	3.30	3.28
3.01	1.52	2.82	2.82	2.82	2.82
2.50	1.26	2.36	2.35	2.35	2.35
1.99	1.32	1.87	1.87	1.87	1.87
1.50	1.00	1.42	1.42	1.42	1.42
1.00	0.66	0.94	0.94	0.94	0.94

Questions

1. For the largest  value of V₁ what is the range of V₃ ?
2. For the largest  value of V₁ what is the percentage uncertainty of V₃ ?
3. For the smallest value of V₁ what is the percentage uncertainty of V₃ ?
4. For the smallest value of V₁ what is the uncertainty of V₁ ?
5. For the smallest value of V₁ what is the percentage uncertainty of V₁ ?
6. Draw a graph of your results on the grid provided
7. Does your line of best fit go through the origin?  Why/ Why not?
8. Were your results accurate?  Why/ why not?
9. What do you think was in the concealed unit?  Why?
10. Draw the circuit for each part of the experiment you did – what were you connecting?
11. How does potential difference split between components in series? In parallel?
12. If given the value of two of the resistors in the network, how could you use your graph to find the third?
13. What is the gradient of the graph of the above results?
14. What does this gradient represent?
15. If R2 = 1 kilo ohm, what is R3?  Use your graph to work this out.

For the above calculation, what is the percentage uncertainty for R3?  Show your working

Turning points questions to do for HW for next Friday

1.Give one reason why Huygens’ wave theory of light did not replace Newton’s theory of light when the fringe pattern due to double slits was first observed. (1)

2.The interference fringe pattern observed by M’n’M on their interferometer did not shift when the apparatus was rotated by 90°. Explain the significance of this null observation. (1)

3.   Discuss the significance of Einstein’s explanation of the photoelectric effect. (2)

4.   Millikan found that the charge on an oil droplet was always in multiples of e. Explain the significance of this result. (1)

5.   What was the significance of Thompson’s calculations of the specific charge of an electron? (2)

In case you lose it - and here are the links for EMPA

A2 EMPA practice questions and sample results

Section 2

l /m	h /m	h /m	h /m	Mean h /m
0.860	0.370	0.365	0.375
0.801	0.503	0.504	0.492
0.724	0.668	0.673	0.672
0.651	0.809	0.812	0.808
0.553	0.945	0.946	0.949

https://www.researchgate.net/publication/252262271_Period_of_an_Interrupted_Pendulum

https://www.youtube.com/watch?v=MEgPkkQSt7s

1. Calculate the means and add to the table.
2. For the largest  value of l what is the range of h ?
3. For the largest  value of l what is the percentage uncertainty of h ?
4. For the smallest value of l what is the uncertainty of h ?
5. For the smallest value of l what is the percentage uncertainty of h ?
6. Draw a graph of your results on the grid provided.
7. What is the pattern shown by these results, and how accurate are they? How do you know?
8. What are the main sources of uncertainty in this experiment? 
9. What equations describe the energy changes involved in this experiment?
10. A pendulum swings from a support post and another post is added to interrupt its swing. We desire to know the maximum height at which the pendulum will perform a full loop around the post. The pendulum requires both potential and kinetic energy in order to complete a full loop. Therefore, it will never be able to return to its height of release while completing a full loop. Ultimately, the pendulum has enough energy to complete a full loop when interrupted at a height equal to two-fifths its initial height of release.
11. How could you use your data to verify the above statement?
12. A student performs a similar experiment but instead measures the maximum height the pendulum reaches once it hits the rod and swings around it.  What would you expect the student to find?
13. Which of your measured values could you use to verify this relationship?
14. Describe the motion of the pendulum on each side of the rod.
15. What is the gradient of the graph of the above results?
16. What does this gradient represent? 

EMPA prep work

Please complete Task 2 on the pendulum and the paper related to task 2, which is Section B Written paper PHA6X Jun 2014 and is in the folder on previous post  - complete this to go though with Dr Casson in your next lesson Monday for 13e and Tues for 13b

Your EMPA will take place in R1 starting at 9am on Friday 22nd April
Thanks
Ms H

EMPA preparation

Link to folder with various relevant EMPA markschemes, tips etc for the AS and A2 EMPA
https://drive.google.com/open?id=0B_-6rEo3ljnVUml5UjNtak05bkk
Enjoy!
Ms H

Markscheme for Jun 11 EMPA for 13b

Click on the link below

https://drive.google.com/open?id=0B_-6rEo3ljnVTm50c29fX1VEZTA
Thanks
Ms H

Photoelectric effect work

Dear Year 13
Here is the ppt on the photoelectric effect as promised, technology failure means it is without my commentary and just an old fashioned ppt, but has all the key information.  Voiceover version will hopefully follow at end of holidays, sorry
Enjoy!
https://docs.google.com/presentation/d/1yrLcDDYhQTMOUhKSPF0gMfjnS8X_xwSgF_qvSB9vbBI/edit?usp=sharing
Ms H